Question

I didn’t see Laura at the party last night. Do you know _______?

A．why didn’t she come	B．what happened
C．when would she arrive	D．where she has been

Answer 1

B

考察宾语从句。宾语从句的考察点：1.连接词；2.语序；3.时态。先从宾语从句的语序入手，应选择陈述句语序，排除A,C，再根据时态，应选择过去时态。故选择B。其中what做主语。