Scientists think they have _____ in their attempt to find the causes of some major dieases.
#81772
A
broken through
B
worked out
C
fallen out
D
got round
推荐题目
This page needed _____ again.
#65214
A
being checked
B
checked
C
to be checked
D
to check
As is well known, carelessness and irresponsibility _______ many deadly accidents. 
#71354
A
lead to
B
result from
C
contribute to
D
result in
I don’t care whatever difficulty I will have _________ this survey.
#78519
A
conduct
B
to conduct
C
conducted
D
conducting