从A，B，C，D四个选项中选出与划线部分意义相同或相近的选项。

1. He was too tired and fell asleep soon.  

A. go to bed     

B. went to sleep

C. went asleep  

D. got to asleep

2. Watch out! There is an iceberg ahead.  

A. Look out     

B. Take out 

C. Be sure      

D. Look for 

3. This is a computer of my own.    

A. a great computer  

B. a new computer  

C. my personal computer   

D. a personal computer 

4. That was a quite and calm night.    

A. silent                 

B. peaceful   

C. peace                 

D. peacefully 

5. He studies hard so as to pass the biggest exam.    

A. so that                

B. in order that    

C. in order to            

D. get to

玉米花药培养的单倍体幼苗，经秋水仙素处理后形成二倍体植株，下图是该过程中某时段细胞核DNA含量变化示意图。下列叙述错误的是：（）

A.a-b过程中细胞不会发生基因变化

B.c-d过程中细胞内发生了染色体数加倍

C.c点后细胞内各染色体组的基因组成相同

D.f-g过程中同源染色体分离，染色体数减半