关于胎儿血液系统的特点，下述哪些是正确的（） A.胎儿血液循环在受精后3周末建立 B

用括号中所给单词的正确形式填空。

1. Father's Day is on the _____ (three) Sunday of June.

2. The population in China is much _____ (large) than that in Australia.

3. I haven't seen my grandma for a long time. I' m looking forward to _____ (visit) her soon.

4. Peter and Simon enjoyed _____ (they) at the English party last night.

5. We were discussing the details of the charity show when the teacher _____ (come) into the classroom.

6. Tom never does his homework as_____ (good) as his cousin. He makes a lot of  mistakes.

7. At the exhibition, the little boy's _____ (invent) attracted many IT engineers.

简述桥梁施工组织设计要点？

用化学灭菌法进行器械灭菌时，应浸泡器械（）时间才有效。

A、30分钟

B、20分钟

C、10分钟

先天性肥厚性幽门狭窄的临床表现，主要有（）

A.呕吐后不爱吃奶

B.喷射样呕吐

C.有胃蠕动波

D.摸到橄榄样包块

E.生后3~4后出现呕吐

将两种或两种以上聚合物进行共混的目地在于（）；决定共混聚合物性能的主要因素是两种聚合物之间的（），如果混溶性好，则形成（），混溶性不好则形成（）。