Please write a report _______ the above subjects are to be covered.
B
inwhichtheabovesubjectsaretobecovered是report的定语从句。which指代先行词report，in用于与report搭配。
Thefarmingmethodshavebeen________improvedwiththeinventionofthenewmachine.
Since we have a focused subject ，we should not talk ________.
_______, could you get me a Turkish conversation book?
Iunderstoodfromherthatyouundertookotherimportantwork______.