It puzzles the scientists _____ some mammals produce their young _____ others lay eggs.
#30772
A
that; while
B
what; while
C
that; as
D
what; as
推荐题目
—How are you doing all these years, Jim? —Nothing new. Everything is going on _______ it was years ago.
#34375
A
as
B
while
C
when
D
since
How did you manage to get to school on time ______ you missed the school bus?
#79910
A
when
B
if
C
once
D
because
________left the door unlocked must be held responsible for the accident.
#31169
A
Whomever
B
Whoever
C
Whatever
D
Whenever
—Are you ready for Spain?—Yes.I want the girls to experience that________ they are young.
#30059
A
while
B
until
C
if
D
before
The woman was about to open the door _______ she heard a strange sound from inside.
#32259
A
as
B
while
C
when
D
then