---Why are you so excited?
---Peter invited me _______ on a trip to Yuntai Mountain.
---What’s happening there?
---Oh. Let me see. There is a panda ______ which causes the traffic jam(交通堵塞).
---Mr Hu, can you tell us how to learn math well?
---Sure. But remember nothing can be learned _________ hard work.
---Mom, can I leave my homework for tomorrow?
---I’m afraid not. Don’t _________ what you can do today till tomorrow.
—What are you doing?
— I’m looking ___ the children. They should be back for lunch.
—Did Sam go to the cinema yesterday?
—Yes, we all went there ____ him.