母亲在怀孕期间,要为胎儿提供所需的养料和氧气,排出胎儿产生的二氧化碳和其他废物.母亲和胎儿之间进行物质交换的器官是( )
A:胎盘
B:肾脏
C:肝脏
D:输卵管
⑴Do you want some rice?____ A. Thanks.
⑵What do you want to drink?____ B. Yes, I do.
⑶Can I help you? ____ C. I want some bread.
⑷Here you are.____ D. Water, please.
⑸Do you want coffee or tea?____ E. I want some tea, please.
____oor
①儒家
②道家
③墨家
④法家