This problem may lead to more serious ones if_______ unsolved.

able to practise their traditions,many young Romans _______ illegal behavior, such as stealing, and were usuallythe main suspects when anything went missing

The library needs _______, but it’ll have to wait until Sunday.

Jenny is talking _____ in class. Please tell her to stop.

It ______ that China ______ its first homemade aircraft carrier (国产航空母舰) in the water in Dalian on April 26, 2017.