Matrix addition

matrix ['metrɪks]

n. <数>矩阵;模型;基质;母体，子宫;

matri(mother)+x(名词后缀)→子宫；母体；铸型；模型；母岩

addition [ə'diʃən]

n. 加，增加，附加;[数]加法;增加的人或事物;

Why?

为什么？

Two dollars and seventy-five cents.

二美元七角五分。

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。