______ there are living creatures in the outer space as those on Earth hasn’t been proved so far.
#13957
A
When
B
How
C
If
D
Whether
推荐题目
The course book is a little too difficult, but we can ______ it to suit the needs of the students.
#10871
A
adapt
B
adopt
C
operate
D
abandon
(2013·高考湖北卷)Carbon dioxide，which makes a________between us and the sun，prevents heat from getting out of the atmosphere easily，so the earth is becoming warmer.
#11928
A
difference
B
comparison
C
connection
D
barrier
By the end of last month, we had sold ____________ as we did last year.
#14199
A
as twice many cups
B
twice cups as many
C
twice as many cups
D
as many cups twice
The official ________ to say more about the plan, so the details of it remain secret.
#11127
A
agreed
B
declined
C
attempted
D
declared