—Must we keep the window open all the time? A. No, you mustn’t B. No, you can’t. C. No, you don’t have to.
It’s easy __________you to say sorry, but remember __________ be late again.
Students should pay attention to __________ the teacher in class.
Sam was __________to make so many mistakes in the English exam.
Kate can dance very well, but she never shows off. She is very__________.
__________world we live in is __________world full of colours.