设坡角为α，
则tanα=1：2，
解得：α=45°．
故答案为：45°．
Many teenagers are made _____ what they're not interested in . [ ]
A. do
B. to do
C. did
D. doing
翻译题。
1. have trouble with sb./sth.__________________
2. have trouble (in) doing sth.__________________
