Mary ________ her homework last night because she was ill.
Cindy is always helpul. She only thinks of others and does not_____herself.
— Jim, what did I say just now? — Sorry, I ______ of something else.
The boy looked __________ because he didn’t pass his maths test.
I think there will be _____ people and ______pollution.
-- Must I do my homework right away? -- No, you _____. You_____ do it later.