1.a small smile turnde up the corners of her mouth.在这个短语中,我认为up一词后缺少一个介词,表示“在”她的嘴角。如果不加,似乎在语法上讲不通啊!到底应该怎么理解?
2.advice of all types as to what people should be doing if they wish to improve their health这个短语中的should be doing一处的时态如何理解?为什么用should be doing而不用shoud do?