David didn’t give up ______ he had failed in the experiment four times.
#58224
A
if
B
while
C
though
D
since
推荐题目
You won’t feel happy at school ______ you get on well with your classmates.
#58383
A
though
B
when
C
unless
D
because
---She broke her mother’s favourite vase______ she stood up. ---It’s a pity!
#55549
A
while
B
as
C
after
D
until
－ Can you help me clean the room?－ OK, _______ I have to wash the clothes first.
#58308
A
so
B
but
C
because
D
as