David didn’t give up ______ he had failed in the experiment four times.
#57729
A
if
B
while
C
though
D
since
推荐题目
---How______ is it from here to the bookstore? --About 20 minutes by bus.
#56289
A
long
B
soon
C
far
D
often
—How big the Green Expo Garden is!—It is. You will get los t easily you have a map or a guide.
#55376
A
unless
B
until
C
if
D
because
