下面哪项不是胎儿血容量降低的原因（）
A.胎盘早剥
B.胎儿脐带部分被压
C.母体低血压
D.产程后期窒息
E.分娩时窒息
参考答案：E
在一直线跑道上放有5粒石子，每粒石子间隔5米．运动员站在距第一粒石子10米处起跑，边跑边捡起石子，捡完后返回起点，运动员跑了______米．
用所给单词的适当形式填空。
1. Do you often hear the song _____ (sing)?
2. How many buildings _____ (go) up during the last few years.
3. It can grow up t0 5 meters or more in _____ (long).
4. King cobra is one of the world's most _____ (danger) animals.
5. The _____ (win) will be given a new bike.
