it remains to be seen ____the new invention will do us a lot of good

题目

it remains to be seen ____the new invention will do us a lot of good
1.whether
2.if
3.that
why?后面做什么成分
whether,为什么？引导主语从句放在后面不是也可以用IF

答案

whether
It remains to be seen Wh--words ……..是否…还有待于看.
注意：不用that,if作连接词