英语：unit1laughter is good for you-grammar and usage教案（牛津译林版选修6）

● Grammar and usage

Step 1: General introduction

This section helps us overview present tenses. You are expected to review the four types of present tense. They are the simple present, the present continuous, the present perfect and the present perfect continuous.

Step 2: Explanation

I The present tense

1 表示客观事实或普通真理.(不受时态限制)

The geography teacher told us the earth moves around the sun.地理老师告诉我们地球绕着太阳转。

Japan lies to the east of China. 日本位于中国的东方。

The sun rises in the east and sets in the west. 太阳东升西落。

处理 SSI 文件时出错