You'd better watch your step or you'll get into trouble again.
你最好留点儿神, 免得再惹麻烦。
What excuse could he have for being so rude?
他做了那样无理的事,将如何辩解呢?
OK, everyone. Less noise, please! Gather round and listen carefully. First we are going to search the beach and the rock pools. Let me remind you what we are looking for: seaweeds, fish, plants, all living things. When you find anything, make a note where