He arrived _______ Shanghai _______ the morning of January 5.
If you want to be healthier, you shouldn't do _____ in the classroom all the time but do more _____ on the playground.
They looked _____ each other and kept their secrets _____ themselves.
Jack had a wonderful time _____ many interesting places in Beijing and he had much time __________ the city.
I have some problems __________ my homework. Could you tell me _____?
The girl _____ a smile on her face is always kind _____ others.