Li Fang is always ready to help others when they are in trouble and he never their request.
A. turns up
B. turns over
C. turns in
D. turns down
网友回答
A. turns up
B. turns over
C. turns in
(答案→)D. turns down
解析：短语辨析。A. 发生；开大 B. 翻阅；翻过来 C. 归还；上交 D. 调低；拒绝。句意：当他们遇到麻烦时，李方总是乐于帮助其他人，他从来不拒绝他们的要求。故选D。