You mustn’t go off on your own, because you______get lost in the mountains.

u have enough to ______ all your daily expenses. — Oh, yes, enoughand to spare.

We should adopt _________ methods to deal with some incidents. You know, anything could occur in that situation.—— I got it. Thank you for reminding me.

It puzzles the scientists _____ some mammalsproduce their young _____ others lay eggs

My father has a very sore throat .— .