Scientists are trying their best to_______ ways to treat the terrible disease caused by Ebola(埃博拉）．
A. come up with B. look forward to
C. talk about D. give up
—What shall we do this Saturday?
— it rains, we’ll have a picnic in Century Park.
A. If B. Unless C. Because D. When
It's a pity that I didn't think of ringing you .
A. earlier B. earliest C. early D. the earliest
To remember things accurately, we don't allow other thoughts our mind.
A. enter B.to enter C. entering D. entered
If you travel around the world, you will be surprised at ________.
A. how different the foreign customs are
B. how the foreign customs are different
C. how different are the foreign customs
D. how are the foreign customs different
-__________ has Line 22 (From Jinshanwei Station to Shanghai South Railway Station) been open to traffic?
A. How far B. How soon
C. How long D. How much
