乙级防火门的耐火极限不低于()h。A．0.7 B．0.6 C．0.8 D．0.9 发布时间：2017-02-28 14:59 │ 来源：www.tikuol.com 题型：单项选择题 问题： 乙级防火门的耐火极限不低于()h。A．0.7B．0.6C．0.8D．0.9
题型：单项选择题 完形填空。 One day Daddy and I went out for a walk. On the way we 1 a lot of people. We went up and 2 a look. Oh, dear! 3 did we see? There 4 a donkey (驴) in the middle of the road. It would not move. The cars and buses could not get past. Then a policeman came. " 5 donkey is this?" he asked. "It's mine," said a farmer, "but I 6 move it."The policeman and the farmer did 7 best to move the donkey, but it would not move. We laughed, butthe 8 of the cars and the buses were worried. "We can't move the donkey," the farmer and the policemansaid. "What shall we do?" "Give him a carrot," my father said. " 9 a good idea!" said the farmer. Soon he found a carrot and showed it to the donkey. When the donkey saw a carrot, it jumped up and walked after the farmer. 10 the cars and buses could get past at last. ( )1. A. saw ( )2. A. enjoyed ( )3. A. When ( )4. A. is ( )5. A. Who ( )6. A. can ( )7. A. his ( )8. A. drivers ( )9. A. He's ( )10. A. Some of B. looked B. had B. Where B. was B. Who's B. can't B. her B. workers B. She's B. Little of C. looked for C. played C. What C. has C. Which's C. could C. their C. riders C. Which is C. All D. watched D. gave D. Which D. had D. Whose D. wasn't D. its D. teachers D. That's D. Few of 查看答案
题型：单项选择题 行业集中度的计算公式为：CRn＝∑xi(i＝1，2，…，n)/∑xi(i＝1，2，…，N)，公式中CRn表示产业中规模最大的前n位企业的行业集中度，n的取值通常为( )。A．80B．40C．2D．8 查看答案