—Why are you going to take part in the high jump in the school sports meet?—Because I am good at ___________A. jump B. jumping C. jumped
_______he is busy, ________he helps us often.
Your child is only five. Is _____necessary for you to be so strict with him?
My mother always has__________ housework to do on weekends.
It’s important ______us to learn English well.
Liu Lei is ________better at Chinese than Liu Ying.