Class-a amplifier

class [klæs]

n. 班;等级;阶级;种类; vt. 把…归入某等级，把…看作（或分类、归类）;把…编入某一班级; adj. 很好的，优秀的，出色的; vi. 属于…类（或等级），被列为某类（或某级）;

amplifier ['æmplɪfaɪɚ]

n. 扩音器;放大器;扩大的人;详述者;

ampli=amplify扩音+fier人或物 →扩音器

and we're trying to resolve that problem.

试图解决这类问题。

If you don't aim high you will never hit high.

不立大志，难攀高峰。

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

00在这里集合，游泳之后再吃午餐。别着急！我们有足够的时间。