--I hear that a famous scientist will come

--I hear that a famous scientist will come to give us a talk. Do you know ______? --About the development of the modern science.A.when he will comeB.when will he comeC.what he will talk aboutD.what will he talk about

C解析此题重点考查宾语从句的时态和语序问题，无论哪种句式结构充当宾语从句都要用陈述句语序，从句的时态要和主句的时态保持一致。

我明天再问问老师，叫他解释下这个问题