Jack is always willing ______ good things with others.
________ you meet, please say hello to him or her.
---Could you tell me _____________? ---OK. Guiyang.
The river is very deep. My mother warns me _________ in it.
She hardly ever speaks English because she is afraid ________ mistakes _______grammar.
I don’t know ______ he will be back ______ the Dragon Boat Festival.