7.Although the causes of cancer ____， we do not yet have any practical way to prevent it.
#105343
A
are being uncovered
B
have been uncovering
C
are uncovering
D
have uncovered
推荐题目
— Why do you do volunteer work in the North-West?— I_______ to improve the lives of the children there through my efforts.
#105303
A
was trying
B
have tried
C
am trying
D
tried
5.―Have you handed in your schoolwork yet? ―Yes，I have. I guess it ____ now.
#105340
A
has graded
B
is graded
C
is being graded
D
is grading
8.Customers are asked to make sure that they ____ the right change before leaving the shop.
#105342
A
will give
B
have been given
C
have given
D
will be given
—What are you putting your shoes on again for?—Because I________you home, that’s all!
#105304
A
drive
B
am driving
C
have driven
D
drove
My money is ____, so I have to call my parents saying that I am missing them.
#105326
A
run out
B
using up
C
running out
D
running out of