把下列句子合并成含有定语从句的复合句，每空一词，使意思基本不变．

Is this the boy? Both his parents are doctors.

Is this the boy ________ ________ ________ both doctors?

把下列句子合并成含有定语从句的复合句，每空一词，使意思基本不变．

It's one of the most important meetings. Many meetings have been held this year.

It's one of the most important meetings ________ ________ ________ held this year.

把下列句子合并成含有定语从句的复合句，每空一词，使意思基本不变．

Is this the first museum? You visited the museum the other day.

Is this the first museum ________ ________ ________ the other day?

把下列句子合并成含有定语从句的复合句，每空一词，使意思基本不变．

He changed his mind at the last moment. This made us very angry.

He changed his mind at the last moment, ________ ________ ________ very angry.

把下列句子合并成含有定语从句的复合句，每空一词，使意思基本不变．

Do you know the boy? We met him in the hospital.

Do you know the boy ________ ________ ________ in the hospital?