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在Visual FoxPro rfl，可以对项目中的数据、文档等进行集中管理，并可以对项目进行创建和维护的是( )。
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假定系统日期是2008年1月13日，则执行命令PI=MOD(YEAR(DATEO)-2000，10)后．PI的值是( )。
Why do we along with 75 other countries—alternate between standard time and daylight time Although many people believe it has an agricultural provenance, daylight time has always been a policy meant to save energy. As Benjamin Franklin argued, if people moved up their summer schedules by an hour, they could live by "sunshine rather than candles" in the evenings. Energy conservation was the motivation for daylight time during World Wars I and II and the oil embargo of the 1970s, and it remains so today—even though there has been little scientific evidence to suggest daylight time actually helps us cut back on electricity use. Recently, however, we were able to conduct a study in Indiana, where daylight time was instituted statewide only in 2006. Before that year, daylight time was in effect in just a handful of counties. This change of policy offered a unique, natural experiment to measure the overall effect on residential electricity consumption. We could compare the amount of energy used by households in the late-adopting counties during the two years before they switched to daylight time with the amounts they used during the year afterward—while using counties that always practiced daylight time as a control group. We found that daylight time caused a 1 percent overall increase in residential electricity use, though the effect varied from month to month. The greatest increase occurred in late summer and early fall, when electricity use rose by 2 percent to 4 percent. Daylight time costs Indiana households an average of $3. 29 a year in higher electricity bills, or about $ 9 million for the whole state. We also calculated the health and other social costs of increased pollution emissions at $1.7 million to $5.5 million per year. What explains this unexpected result While daylight time reduces demand for household lighting, it increases demand for heating in the early spring and late fall(in the mornings)and, even more important, for cooling on summer evenings. Benjamin Franklin was right about candles, in other words, but he did not consider air-conditioners. In regions of the United States where demand for air-conditioning is greater than in Indiana, this spike in cooling costs is likely to be even greater. Arizona, one of the hottest states, may have it right; it does not practice daylight time. Eliminating daylight time would thus accord with President-elect Barack Obama"s stated goals of conserving resources, saving money, promoting energy security and reducing climate change. At the very least, we should abandon the notion that we are saving energy while enjoying the extra hour of sunlight on hot summer evenings. It was in Indiana that a study was conducted because______ .
In recent years, reformers have sought to improve our failing public education system by tightening and standardizing the measures we use to judge performance. From the numerical requirements of the No Child Left Behind Act to California"s increased focus on assessment and accountability, there"s been a conscious attempt to use hard data to measure success at every level of the education system. But one group does not have its performance measured this way: teachers. Determining the effectiveness of individual teachers—are they helping our kids learn or not remains a mostly subjective judgment. Yet there"s no reason why teachers shouldn"t also be evaluated against objective measures of student performance just as are schools, districts and states. Teacher evaluations focus on what they do in the classroom—the input of the learning process. In most school districts, principals show up at prearranged times to observe teachers" work, and then write their observations. In doing this, they typically use a checklist to guide their assessments. Evaluations usually consist of one or two written observations. This superficial and largely subjective approach to evaluating teachers is something of a farce. In many instances, principals can only rate teachers "satisfactory" or "unsatisfactory". Multiple unsatisfactory evaluations can lead to dismissal. But faced with the prospect of battling the local teachers union to prove that a teacher"s unsatisfactory evaluation is valid, most principals capitulate and rate virtually all teachers as satisfactory. This rubber-stamp routine may make things easier for administrators, but not for the kids. Several researchers, among them Eric Hanushek of the Hoover Institution of Stanford University and Jonah Rockoff of Columbia University, have shown that teachers are not interchangeable when it comes to student learning. Given a year with an effective teacher—one whose pupils previously showed test-score gains—students can advance their learning by a grade level or more, according to research done by William Sanders while he was at the University of Tennessee. He also found that under a weak teacher, kids" progress can stall, and they can fall behind. So why not include student test scores—the output of the learning process -in teachers " evaluations Besides giving the evaluation process a much-needed shot of objectivity and rigor, this change could help administrators target assistance for struggling teachers and recognize those who are most effective in the classroom. In its report this month, Gov. Arnold Schwarzenegger"s nonpartisan committee of education experts agreed. Among other things, it recommended that teacher evaluations should be based in part on student achievement. The author proposes that teacher evaluations should______.
In recent years, reformers have sought to improve our failing public education system by tightening and standardizing the measures we use to judge performance. From the numerical requirements of the No Child Left Behind Act to California"s increased focus on assessment and accountability, there"s been a conscious attempt to use hard data to measure success at every level of the education system. But one group does not have its performance measured this way: teachers. Determining the effectiveness of individual teachers—are they helping our kids learn or not remains a mostly subjective judgment. Yet there"s no reason why teachers shouldn"t also be evaluated against objective measures of student performance just as are schools, districts and states. Teacher evaluations focus on what they do in the classroom—the input of the learning process. In most school districts, principals show up at prearranged times to observe teachers" work, and then write their observations. In doing this, they typically use a checklist to guide their assessments. Evaluations usually consist of one or two written observations. This superficial and largely subjective approach to evaluating teachers is something of a farce. In many instances, principals can only rate teachers "satisfactory" or "unsatisfactory". Multiple unsatisfactory evaluations can lead to dismissal. But faced with the prospect of battling the local teachers union to prove that a teacher"s unsatisfactory evaluation is valid, most principals capitulate and rate virtually all teachers as satisfactory. This rubber-stamp routine may make things easier for administrators, but not for the kids. Several researchers, among them Eric Hanushek of the Hoover Institution of Stanford University and Jonah Rockoff of Columbia University, have shown that teachers are not interchangeable when it comes to student learning. Given a year with an effective teacher—one whose pupils previously showed test-score gains—students can advance their learning by a grade level or more, according to research done by William Sanders while he was at the University of Tennessee. He also found that under a weak teacher, kids" progress can stall, and they can fall behind. So why not include student test scores—the output of the learning process -in teachers " evaluations Besides giving the evaluation process a much-needed shot of objectivity and rigor, this change could help administrators target assistance for struggling teachers and recognize those who are most effective in the classroom. In its report this month, Gov. Arnold Schwarzenegger"s nonpartisan committee of education experts agreed. Among other things, it recommended that teacher evaluations should be based in part on student achievement. The author believes that______.
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