—Wang Wei, what are you doing ? —I’m reading ______.
____Lily ___Lucy can go with you , because one of them has to stay here to look after their mother
It`s not easy _______ Chinese students _______English well.
Mother told her son _______do that _______
Who saw it ______ at that time?
More and more people have realized that we won’t have cleaner water to drink unless something _______soon.