Please write a report ________ the above subjects are to be covered.
A、whichB
inwhichtheabovesubjectsaretobecovered是report的定语从句。which指代先行词report，in用于与report搭配。
Whycouldn’tyou________ananswerwhenIaskedyouwhyyouwerelate?
Thegovernmentcalledoutpolicementosuppresstheriot.
NeitherEnglishnorChinese________difficulttolearn.
You’llbetheretomorrow--youwon’t________me________,willyou?
Themissingboyswerelastseen________neartheriver.
