Translation of "Johnson's" in Chinese

Mr. Johnson's room was a large one.

Johnson先生的房間是一間大房間。

Mr. Johnson's room was a large room.

強森先生的房間是一個大房間。

It is clearly shown in Johnson's investigation that passive smoking is very harmful.

在Johnson的调查里，明确地证明了二手烟是很有害的。