声音在空气中的传播速度是________m/s,如果看到闪电后,3s钟才听到雷声,那么闪电处距人约________m。
340,1020
动词填空。
1. There __ (be) some milk and meat in the fridge.
2. It's time for you _ (get) up.
3. One of my friends ______(come) from HK.
4. Tony, ______ (not climb) the tree, please.
5. Let's go______ (swim) in the swimming pool.
6. Why not __ (write) the letter with a pen?
7. How many lessons______ your classmates______(have) on Mondays?
8. Lily, would you like ______(look)after my pet?
9. What about ______(chat) with me on the Internet?
10. Daniel with his parents __ (fly) a kite in the park on Sundays.
长期喝酸奶有哪些好处?