___________there are many different types of food, some animals spend their lives eating only one type.
#31689
A
Since
B
Unless
C
Once
D
While
推荐题目
Find ways to praise your children often,_____ you’ll find they will open their hearts to you.
#32927
A
till
B
or
C
and
D
but
I didn’t realize my mistake ________ my teacher had a facetoface talk with me.
#32640
A
until
B
after
C
since
D
when
—How do you think I can make up with Jack?—Set aside ________ you disagree and try to find what you have in common.
#30321
A
what
B
where
C
whether
D
which
_____ the Internet brings much profit in, it can cause o lot of social problem.
#80454
A
If
B
While
C
Once
D
When