Zhi Yueying ， unusual teacher， has taught in a village school for 37years．（　　）

A．/B．aC．anD．the

It takes us less time to go to Beijing because the of trains has increased a lot．（　　）

A．priceB．speedC．spaceD．service

This is a private letter Tom． Nobody else can open it．（　　）

A．forB．withC．fromD．about

In order to sell more products， we need to come up with more ideas．（　　）

A．trueB．commonC．simpleD．creative

To our surprise， the computer won the chess game against the human player．（　　）

A．certainlyB．usuallyC．finallyD．mostly