Children’s brains can’t develop properly_______ they lack protein(蛋白质).
Though he was disabled, he was never satisfied ______ he did the best of a normal child.
Could ______ that have a say in the decision do us a favor about the problem?
Which do you enjoy ______ you weekend, doing sports or watching TV?
She ______ stop whomever she met to tell the story about her Ah Mao.
______, his idea was actually worth practicing.