With his attention________on the shops along the roadside，he knocked an old man down while riding to school.

A  concentrating     B．concentrated     C．to concentrate      D．concentrates

答案　B

解析　考查词组，故选B项。

从所给的四个选项中选择最佳答案

_______ Paris, they called at the wine shop of Monsieur Defarge．

[　　]

A．As soon as they arrived　　　B．On reaching in

C．On their arrival in　　　　　 D．At their arriving

从所给的四个选项中选择最佳答案

We ______ they will come to attend the meeting．　　　

[　　]

A．are not sure about　　　B．are not sure whether

C．are not sure　　　　 　D．don' t sure whether

从所给的四个选项中选择最佳答案

　　 [　　]

A．direction　　　B．way　　　C．street　　　D．path

从所给的四个选项中选择最佳答案

Look! They seem ______ something on the fire over there．　　　

[　　]

A．to cook　　　　　　B．to be cooking

C．to have cooked　　　D．to cooking