15. _______ the day went on, the weather got worse, which made it impossible for them to go down the mountain.
—Do you know why Lisa cried in class?—I don't know and I don't ________.
Many teens don't get enough sleep because they have too much homework to do, which ________ them up at night.
Freddy made up his mind to enjoy his singing and to________ as many happy experiences as he could.
The Chinese government has overcome problems of population and economy to ________ its “nine years of compulsory education”.
—How did you find the film The Flowers of War? —It's very moving. I couldn't ________ my tears.