--It’s really nice of you to help me!--_________A. My pleasure. B. Don’t say that C. Is that so?
It's very dangerous __________ football in the street.
-- ________ you tell me how to write it in English? -- I'm sorry, I can't.
Look! They ________ in the hallway.
Can you help me ________ my homework?
The teachers ________ on the blackboard with chalk in the future.