How do you learn English —I learn English by _________.

Will you go to Mary’s birthday party?—No, ____ invited, I can’t go to itI’ll be too busy then

It is good manners to eat up ______ is left in your plate.

Can we go camping tomorrow，as planned—I’m afraid not. The dark clouds aheavy rain.

_______ have you been friends . -We have been friends since we were young.