是How to answer还是What to answer

He doesn't know () to answer

楼上的错了哦，应该用what
如果用how的话，从句 how to answer 缺宾语，
故，用how ,应表达为He doesn't know how to answer it
而what 本身是可以当宾语的，故可以直接用what to answer。

可以参考，希望对你有帮助O(∩_∩)O~

c 试题分析：句意：他们是多么难的问题呀！我不会回答它们。感叹句一般有两种结构：what +(a/an)+形容词+名词+主语+谓语！名词是复数或不可数名词，不加a/an.how+形容词+主语+谓语！questions复数，所以根据感叹句的结构选c

用what. 跟what to do & how to do it一样理解； how是绝对错误的！

what to anser 如何回答。 He doesn't know (what) to answer 依然是 what 希望帮到你，望采纳，谢谢。