It's uncertain ______ the experiment is worth doing.A.if B.that C_其他解答

It's uncertain ______ the experiment is worth doing.
A.if B.that C.how D.whether

人气：473 ℃　时间：2020-03-07 12:41:48

解答

D
uncertain 是不确定,而后面却是一个陈述句,所以用whether