The policy of the mainland is very clear and  straightforward，and the key problem is_____the  leaders of Taiwan will accept it.

A．that

B．how

C．why

D．whether

正常妊娠38周时的羊水量约为

A．500～800ml

B．800～1000ml

C．1000～1500ml

D．1200～1600ml

E．1500～2000ml