问题
选择题
While typing, Helen has a habit of stopping ______ to give her long and flowing hair a smooth.
A now and then B.over and over C.up and down D.here and there
答案
答案：A
题目分析：now and then时而，不时； over and over反复，再三； up and down上上下下； here and there到处。句意是打字时，海伦有一个习惯，不时停下来捋一下她的头发。故选A。
点评：固定词组辨析题是考查题，要求考生平时加强这方面的记忆和积累。根据具体语境进行选择。