新概念英语2册48课，这些句子为什么没有宾语？

Question

Dentists always ask question when it is impossible for you to answer.
请问answer后面怎么没有宾语？
Meanwhile,my tongue was busy searching out the hole where the tooth had been.
请问had been后面怎么没有宾语？
我还遇到好多类似的句子，请问这是为什么啊？

Answer 1

在这个it is impossible for you to answer的结构中的answe是不需要接宾语的，因为他的宾语就是前面的it
这和it is difficult for us to learn English 是不同的，这里的it 只是一个形式主语
第二个句子中 where the tooth had been 是一个定语从句， where指代就是前面的the hole，如果要分成两句话来看就是
Meanwhile,my tongue was busy searching out the hole， the tooth had been in the hole.
改成定语从句的时候，用which替代前面的the hole 和in一起构成in which一起做引导词，而in which 在那个地方，可以换成where， 所以就有了这个句子

你明白了吗？

Answer 2

Dentists always ask question when it is impossible for you to answer.
请问answer后面怎么没有宾语？

有一种东西 叫省略

Meanwhile,my tongue was busy searching out the hole where the tooth had been.
请问had been后面怎么没有宾语？

有一种东西叫定语从句

请学好语法