问题

Children’s brains cannot develop properly _________ they lack protein

A:because
B:since
C:hildren’swhen
D:unless

正确答案是：

同类题型

Mulan is exciting movie. It comes from very old Chinese story.

下列各句中划线的成语能被括号中的成语替换且符合句意的一项是

Being ________ for interviews is very important if you want to find a good job.

The_____ expression on the girl’s face suggested that she was _____ the _____ toys. [ ]

Is the door of the bedroom _______ or _________, mum