题干
Many students write to Language Doctor to _______ advice about learning English.
A：look though
B：ask for
C：give up
D：worry about
答案(点此获取答案解析）
B
Many students write to Language Doctor to _______ advice about learning English.
A：look though
B：ask for
C：give up
D：worry about
；④AD=BD cos45°．其中正确的一组是（ ）