Evidence has been found through years of study______children’s early sleeping problems are likely tocontinue when they grow up.

The young man invited the lady to dance with him, but she ______ his invitation．

_______I come back before five o’clock—No, you ________. But you________ be back later than seven o’clock

day’s fiercely competitive society,； people only care about what achievements you _______, not your efforts.

I was ________ at the letter, which was ________ to my classmates..