把下列句子合并成含有宾语从句的句子
Where is the headmaster?I want to know it.
I want to know 【】
He can”t work out this difficult math problem.I think.
I 【】 think 【】 he 【】 work out this difficult math problem.
The students of Class One Work hard.The teacher said to us.
The teacher 【】 us 【】 the student of Class One 【】 hard.
The earth is bigger than the moon.The boy said to us.
The boy 【】 us 【】 the earth 【】 bigger than the moon.
The driver said to them.People here like to take buses.
The driver 【】 them 【】 people here 【】 to take buses.