Themissingboyswerelastseen________neartheriver.
A
所填的词为主语补足语，因其后有明确的地点，补足语表示动作当时正在进行中，所以只能使用 playing 。
Thegovernmentcalledoutpolicementosuppresstheriot.
Pleasewriteareport________theabovesubjectsaretobecovered.
WhichofthefollowingcountryisnotamemberofOECD?
WhichofthefollowingstatementisNOTtrue?
Hefound_______difficulttostudymaths.
