The famous scientist was going out _____ he found himself surrounded by lots of young people.
#34549
A
when
B
before
C
while
D
after
推荐题目
There is no way of knowing why one man makes an important discovery ______ another man, also intelligent, fails.
#30143
A
since
B
if
C
as
D
while
Bad habits, _______ formed, are difficult, and sometimes impossible to shake off.
#31345
A
before
B
once
C
until
D
unless
Children’s brains can’t develop properly_______ they lack protein.
#79950
A
when
B
since
C
because
D
unless
cycling is a fantastic way to burn a few calories and save some money, there still exist risks．
#31065
A
Since
B
While
C
As
D
When