问题

In many countries, some scientistsare already _______ research in order to produce a cloned human baby.

A:left
B:coming up with
C:putting forward
D:pushing ahead with

正确答案是：

同类题型

选出对下面加点的字词解释有误的一项是（）

Although this medicine can cure youyour illness, it has a bad effect____you

His father and mother often argue _______what TV programmes _________.

He ________ late for school.

In my opinion he is a little upset _____ what I mentioned above[ ]