胚胎发育时从母体获得所需养料和氧的结构是（ ）
A．卵巢
B．子宫
C．胎盘和脐带
D．输卵管
怀孕是从胚胎从输卵管移动到子宫内，着床在子宫内膜开始．当胚胎成功着床后，胚胎发育到第8周末，其外貌开始像人，从此称作胎儿．胎儿生活在子宫内半透明的羊水中，通过胎盘、脐带从母体获得所需要的营养物质和氧气，胎儿产生的二氧化碳等废物，也是通过胎盘经母体排出体外的．
故选：C
| 根据应答语从方框中选出适当的问句补全对话。 | |
| Peter: 1 ? Linda: I'm going to be a teacher when I grow up. Peter: 2 ? Linda: I'm going to work harder in school this year. And I'm going to get a part-time job. Peter: 3 ? Linda: I want to put some money in the bank. I'll need money for college. Peter: 4 ? Linda: I want to work with computer. Peter: That sounds great!
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