相量图如下所示,其正弦电压U施加于感抗XL=5Ω的电感元件上,则通过该元件的电流相量I=()。
A. 5∠-60°A
B. 5∠120°A
C. 2∠-60°A
D. 10∠120°A
查看答案
如图所示三种截面形状,均是由面积为A的大矩形挖去面积为S的小矩形而构成的,z轴为中性轴,则可按公式Iz=Iz大矩形-Iz小矩形计算其对中性轴的惯性矩的是()。
A. 只有图(a)截面
B. 只有图(b)截面
C. 只有图(c)截面
D. (b)、(c)截面均可
以下四个投资方案,经筛选,最佳投资方案是()。
A. 甲方案
B. 乙方案
C. 丙方案
D. 丁方案
SAN FRANCISCO—The "Reading Wizard" (阅读巫题) , an 11-year-old boy, whose offer to read to children without being paid at a local library was refused by libraries will get to read to younger
kids after all.
Mayor Willie Brown last Wednesday ordered San Francisco Public Library officials to allow John O'Connor to read to preschool children to get them interested in books and stop them from watching television and video games.
"I didn' t expect this kind of attention." John said, "It's just shocking."
John has chosen his first book, "The king' s Giraffe", and made up fliers inviting neighborhood children, aged from three to six, to the Presidio Branch every Wednesday afternoon. He planned to call himself the "Reading Wizard" and wear a special hat, fake glasses and a black coat.
But his idea was refused on the phone, in person and finally with a letter from Toni Bernardi, the chief of the library's children and youth service. Using terms like "appropriate material"(适龄读物), she wrote that only library workers are allowed to read to children.
John then went to a member of the city board of supervisors(督导董事会) ,who advised him to write letters to the library officials.
Who is the "Reading Wizard"?
A. Presidio Branch.
B. The King's Giraffe.
C. John O'Connor.
D. Toni Bernardi.
ABC会计师事务所派遣L注册会计师对Y公司2006年度会计报表进行审计。在审计过程中,发现了若干报表之间的勾稽关系和重大事项,请代为做出正确的专业判断。
现金流量表补充资料中“经营性应收项目的减少(减:增加)”栏的数额,应等于同期资产负债表“应收账款”项目的期末数减去期初数的差额。()
A. 正确
B. 错误