Although the causes of cancer_____, we do not yet have any practical way to prevent it.
#104936
A
are being uncovered
B
have been uncovering
C
are uncovering
D
have uncovered
推荐题目
---Hi, Tracy, you looked tired.---I am tired. I______the living room all day.
#101772
A
painted
B
had painted
C
having been painting
D
have painted
(2013·高考四川卷)Hurry up,kids!The school bus________for us!
#99694
A
waits
B
was waiting
C
waited
D
is waiting
一Why do children hang stockings over the fireplace for presents?一As the story goes, to help a poor family, Father Christmas threw a small bag of gold down the chimney and it fell into a stocking that_up to dry over the fireplace.
#99591
A
hung
B
had hung
C
was hanging
D
was hanged
I _____ up early when I was in high school, but now I _____ up around 7:00 am.
#103034
A
used to get; used to get
B
am used to getting; used to get
C
used to get; am used to getting
D
am used to getting; am used to getting
Amy insists that she ____ the secret to lose weight. But she won’t share it with us.
#101092
A
had discovered
B
discovers
C
has discovered
D
will discover