1、He got to the cinema.The film had begun.(用before连接两个句子）2、I was watching television in the living room.The telephone rang.(用when连接两个句子

1The film had begun before he got to the cinema
2I was watching TV in the living room when the telephone rang

Before he got to the cinema, the film had begun. 可交换位置。
注意逻辑关系，had begun 是过去完成时，所以不可能是He got to the cinema before the film had begun
I was watching television in the living room when the telephone rang.

When the telephone rang,I was watching television in the living room.
Before he got to the cinema,the film had begun.

Before he got to the cinema，the film has begun.
The telephone rang when I was watching television in the living room.

He got to the cinema before the film had begun.
I was watching television in the living when roomhe telephone rang

He got to the cinema before the film had begun。
I was watching television in the living when roomhe telephone rang