The Arctic, which is abundant in oil, _____ second only to the Middle East, is ______ home to seals.

e arguing on who, on earth, is knownfor the great discovery penicillin,an effective bacteria killer.

can chatwith your friends, makes communication easy.

Olympic Games, only athletes whohave reached the agreed standard for their event will be ______ as competitors．

You’d better cut your hair short. Our school doesn’t _______ long hair.