问题 单项选择题 A1/A2型题

牙本质的胶原纤维主要为()

A.Ⅰ型胶原

B.Ⅱ型胶原

C.Ⅲ型胶原

D.Ⅳ型胶原

E.Ⅴ型胶原

答案

参考答案:A

解析:大量研究已证实牙本质中的胶原主要为Ⅰ型,约占95%,其次为Ⅴ型,约占3%。

写作题
模仿写作:
     汶川地震,全国很多地方都有震感。请你根据下面方框中所给词语,模仿Sandra对当时经历的描述,把Benny的描述补充完整。字数60-80。
     Sandra: I was almost asleep when I felt the bed rocking. Suddenly I noticed our blinds (百页窗) moving. So
I quickly looked around to see what was happening. I found my ceiling fan was moving although I had turned it
off a moment ago. I quickly woke up my children and we left the building as quickly as possible.
feel my chair moving and see the computer shaking       hear noises coming from the shaking window
see what is going on       shake as if it is going to fall       wake up my housemates
     Benny: I was in my office                                                                                                                     
                                                                                                                                                               
                                                                                                                                                              
 
单项选择题