57里面有（）个十和（）个一。

单词拼写

1. The shirt is of better q______________ than that one, so it costs more.

2. My first a____________ at a chocolate cake tasted horrible.

3. My father likes to read d____________ stories about Sherlock Holmes(夏洛克. 福尔摩斯)

4. Harry is helpful and humorous. He makes a good c___________ on my trip.

5. He was disappointed because he had not p_________ well in the game.

6. All your changes of plan have made it totally ____________(迷惑不解的).

7. The subject is rather complex,and hard to ________________ (简化).

8. The ____________(志愿者)for community service are doing a good job.

9. The university is trying to make more accommodation ____________(可获得的)for students.

10. I will try my best, but I can't ____________(保证) that I'll win.

11. Her ____________(优雅的)manners impressed all the people present at the party.

12. This kind of apples is more expensive because they are ________________(进口)from abroad.

13. He lived under the ________________(保护)of a strong and brave chief.

14. ____________(比较) with her mother, she is tall.

15. In 1862 the American slaves won their ________________(斗争)for freedom.

下列对遗传物质探索历程有关的叙述中错误的是[ ]

A．肺炎双球菌转化实验中所用到的R型细菌是无毒性的，S型细菌是有毒性的

B．在艾弗里肺炎双球菌转化实验中，细菌转化的实质是发生了基因重组

C．在噬菌体侵染细菌实验中，用³²P、³⁵S分别标记噬菌体DNA和蛋白质单独观察实验结果

D．噬菌体侵染细菌实验中，能得出DNA是主要的遗传物质的结沦

项目总投资的构成是( )。

A．建设投资

B．建设期利息

C．流动资金

D．固定资金

E．可变成本

蚕吐丝发生在它个体发育的什么阶段（       ）

A．成虫

B．幼虫

C．受精卵

D．蛹