题目内容

甲、乙两种不同种农药共1000g,其中甲种农药的浓度是乙种农药浓度的2倍,将甲乙两种农药混合后,容器中农药的浓度为12%. (1)乙种农药600g;(2)甲种农药浓度为16%.()

A. 条件(1)充分,但条件(2)不充分.
B. 条件(2)充分.但条件(1)不充分.
C. 条件(1)和(2)单独都不充分,但条件(1)和条件(2)联合起来充分.
D. 条件(1)充分,条件(2)也充分.
E. 条件(1)和条件(2)单独都不充分,条件(1)和条件(2)联合起来也不充分.

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方程|1-|1+x||=a只有两个不同的解. (1)a≥2;(2)0<a<1.()

A. 条件(1)充分,但条件(2)不充分.
B. 条件(2)充分.但条件(1)不充分.
C. 条件(1)和(2)单独都不充分,但条件(1)和条件(2)联合起来充分.
D. 条件(1)充分,条件(2)也充分.
E. 条件(1)和条件(2)单独都不充分,条件(1)和条件(2)联合起来也不充分.

A man once said how useless it was to put advertisements in the newspapers. "Last week," said be, "my umbrella was stolen from a London Church. As it was a present, I spent twice its worth in advertising, but didn’t get it back.""How did you write your advertisement" asked one of the listeners, a merchant."Here it is," said the man, taking out of his pocket a slip cut from a newspaper. The other man took it and read, "Lost from the City Church last Sunday evening, a black silk umbrella. The gentleman who finds it will receive ten shillings on leaving it at No. 10 Broad Street.""Now," said the merchant, "I often advertise, and find that it pays me well. But the way in which an advertisement is expressed is of great importance. Let us try for your umbrella again, and if it fails, I’ll buy you a new one." The merchant then took a slip of paper out of his pocket and wrote: "If the man who was seen to take an umbrella from the City Church last Sunday evening doesn’t wish to get into trouble, he will return the umbrella to No. 10 Broad Street. He is well known." This appeared in the paper, and on the following morning, the man was astonished when he opened the front door. In the door way lay at least twelve umbrellas of all sizes and colors that had been thrown in, and his own was among the number. Many of them had notes, fastened to them saying that they had been taken by mistake, and begging the loser not to say anything about the matter. Did the merchant know who had taken the umbrella()

A. Sure.
B. Not very sure.
C. Not at all.
D. Probably.

A man once said how useless it was to put advertisements in the newspapers. "Last week," said be, "my umbrella was stolen from a London Church. As it was a present, I spent twice its worth in advertising, but didn’t get it back.""How did you write your advertisement" asked one of the listeners, a merchant."Here it is," said the man, taking out of his pocket a slip cut from a newspaper. The other man took it and read, "Lost from the City Church last Sunday evening, a black silk umbrella. The gentleman who finds it will receive ten shillings on leaving it at No. 10 Broad Street.""Now," said the merchant, "I often advertise, and find that it pays me well. But the way in which an advertisement is expressed is of great importance. Let us try for your umbrella again, and if it fails, I’ll buy you a new one." The merchant then took a slip of paper out of his pocket and wrote: "If the man who was seen to take an umbrella from the City Church last Sunday evening doesn’t wish to get into trouble, he will return the umbrella to No. 10 Broad Street. He is well known." This appeared in the paper, and on the following morning, the man was astonished when he opened the front door. In the door way lay at least twelve umbrellas of all sizes and colors that had been thrown in, and his own was among the number. Many of them had notes, fastened to them saying that they had been taken by mistake, and begging the loser not to say anything about the matter. This is a story about()

A. a useless advertisement
B. how to make an effective advertisement
C. how the man lost and found his umbrella
D. what the merchant did for the umbrella owner

A man once said how useless it was to put advertisements in the newspapers. "Last week," said be, "my umbrella was stolen from a London Church. As it was a present, I spent twice its worth in advertising, but didn’t get it back.""How did you write your advertisement" asked one of the listeners, a merchant."Here it is," said the man, taking out of his pocket a slip cut from a newspaper. The other man took it and read, "Lost from the City Church last Sunday evening, a black silk umbrella. The gentleman who finds it will receive ten shillings on leaving it at No. 10 Broad Street.""Now," said the merchant, "I often advertise, and find that it pays me well. But the way in which an advertisement is expressed is of great importance. Let us try for your umbrella again, and if it fails, I’ll buy you a new one." The merchant then took a slip of paper out of his pocket and wrote: "If the man who was seen to take an umbrella from the City Church last Sunday evening doesn’t wish to get into trouble, he will return the umbrella to No. 10 Broad Street. He is well known." This appeared in the paper, and on the following morning, the man was astonished when he opened the front door. In the door way lay at least twelve umbrellas of all sizes and colors that had been thrown in, and his own was among the number. Many of them had notes, fastened to them saying that they had been taken by mistake, and begging the loser not to say anything about the matter. The result of the first advertisement was that()

A. the man got his umbrella back
B. the man wasted some money on advertising
C. nobody found the missing umbrella
D. the umbrella was found somewhere near the church

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