They want to know () do to help us A.what the can B.how they can 为什么不选B?要具体原因
问题描述：
They want to know () do to help us A.what the can B.how they can 为什么不选B?要具体原因
答
他们想知道他们能做什么来帮助我们.只能选 A.如果想用 how,就把原句改成：They want to know how they can help us.