It is (polite) to talk loudly in public places like a library.
Telescopes are (有用的).We can look at the universe through them.
﹣Could you pass me those (盒子)?
﹣Certainly.Here you are.
Last year Susan gave a /'flauə/to Ms.Lu on Teachers'Day.
The new hotel will be built /bi'said/the river.
We must try our (our/ours) best to protect plants.They're important to human beings.