英语翻译1．中学生既不应该吸烟,也不应该饮酒.2．不要让它们影响你.　　3．吸烟有害健康.　　4．请热烈欢迎我们的校长.

Middle school student should neither smoke nor drink
Don't let it influence you
Smoking is harmful to our body
Please welcome our principal
No one knows all their names
What's the present population of the world
The population of china is about 1.3 billion