三σ规则

【化】 three-sigma rule

1. 他只是一个三岁的孩子。
   He is only a child of three.
2. 海洋几乎占地球表面的四分之三。
   The sea covers nearly three-fourths of the world's surface.
3. 她用功的程度是我的三倍。
   She studies three times as hard as I.
4. 他用功的程度是我的三倍还不止。
   He studies more than three times as hard as I.
5. 他的财富是我的三倍还不止。
   He is more than three times as rich as I.
6. 这条街比那条街宽三倍。
   This street is three times wider than that one.
7. 我已经写了三个小时了。
   I've been writing for three hours.
8. 我学西班牙语已经三个月了。
   I've been studying Spanish for three months.

规则的英语翻译：