小小英语语法Smoking is harmful to healthTo smoke is harmful to health有什么区别,我想问的是什么时候加ing,什么时候加to,什么时候加原形

小小英语语法Smoking is harmful to healthTo smoke is harmful to health有什么区别,我想问的是什么时候加ing,什么时候加to,什么时候加原形 英语语法问题：“Smoking is harmful to health”“Smoking is harmful to health”一句中“smoking”可以换成“To smoke”吗?为什么?另：系动词是什么?（希望解释得易懂一点） smoking is allowed 为什么用smoking? Someone is smoking.对smoking提问 Smoking is good for your health.Smoking is ( )( )your health. 英语作文 smoking is harmful Smoking is committing suicide slowly 高一英语语法题 一些动词的用法 we all felt ____after we took,the 90-minute exam.A relaxing B.relaxed C.to be relaxing D.relaxwhy cam't I smokeAt no time ___in the reading-room.A does smoking permit B is smoking permittedC smoking is perm 一个小小的英语语法问题There is no need to know it.There is no necessity to know it.两个都是“没必要知道这件事”的原意 smoking smoking Smoking is harmful to your health. what is the effects of smoking? It is not allow smoking here there is no fire without smoking here Little is done to stop smoking是什么意思 Smoking is bad for p___ health 英语语法求教A cook will be immediately fired if he is found____in the kitchen.为什么要用smoking 我用to smoke不行吗?例如说He was seen to.这不是一样的句型吗?