You should give up _______basketball.

They have held several meetings to _____ next year’s production plans.

Why are you walking to school, Miss Lin —Because my car broke down on the way.

Do you think you will be able to finish your writing by five o’clock today? — ______. I’ll be busy with experiments all day.

Qian Xuesen tried many times _________ he found thesolution to the puzzle about space technology.