____ bikes are red. ____ are blue.
─Do you know_____second-hand smoke? ─To protect our health and memory.
We all know that we’ll meet all kinds of difficulties in our lives in the future. We should learn to be ________ any challenge!
—My cousin is good at all his subjects at school, but he never ________.—What a ________ boy! We should learn from him.
My best friend Alex failed in the math competition. I’d like to _________.
It’s creative _______ you _______ this good idea.