We'll go to visit Tian'anmen Square ________ it doesn't rain tomorrow．

1. A.
   if
2. B.
   as soon as
3. C.
   when
4. D.
   since

We won't go to the Great Wall if it ________ tomorrow．

1. A.
   snows
2. B.
   snowed
3. C.
   snow
4. D.
   will snow

We hope that as many people as possible ________ join us for the charity show tomorrow.

1. A.
   need
2. B.
   can
3. C.
   must
4. D.
   should

We will stay at home if my aunt ________ to visit us tomorrow.

1. A.
   comes
2. B.
   will come
3. C.
   is coming
4. D.
   come

We will climb the mountain tomorrow_ it doesn't rain.

A. if B. although    C. since