有一条从东向西流的河流，南岸侵蚀较厉害，且一年内两次太阳直射，该河流可能位于[ ]
A、40°S
B、40°N
C、20°N
D、20°S
答案：D
—Can you tell me Kitty's address.
—I don't know, either. But I'll tell you her address as soon as she _____ to me.[ ]
A. writes
B. write
C. wrote
D. written
简述什么是问题解决？
