I don't know what books he likes reading.
what 在这里引导宾语从句,作定语修饰从句的宾语books
请及时采纳,不懂继续问( 天天在线 ）
(*^__^*) 祝学习进步! 谢谢!(8)It is not always easy for the public to see ______ use a new invention can be of to human life.何解？？？what有时要让公众知道一项新的发明对人类生活有什么用途并不总是那么容易。