Walking is good for our health. Milk is good for children.

　②product指任何体力劳动或脑力劳动所生产的东西，含义最广，是可数名词。

　　production指生产的动作或产量，也指生产的结果，还特指艺术作品。

　　produce作名词时，指农产品、天然产物或工业产品的总称，是不可数名词。

12．We also make choices based on how the products are grown or made: environmentally friendly foods, or "eco-foods", are made by companies who have tried to use green and clean ways to make the foods.

　①based on how the products are grown or made是过去分词短语作方式状语，如：

　　We'll spend the night locked in your room.

　②foods表示各种各样的食品，所以用了复数，若单纯表示数量，则food是不可数名词。

13．Because we have so much to choose from, many companies and stores offer advice about what we should eat.

　to choose from是后置定语，修饰so much，构成动宾关系。

　choose与choose from的辨析

　choose意为"选中"，"选出"

　choose from意为"从......中挑选"，from后接选择的范围

　Have you chosen a hat yet? There're different kinds of toys to choose from.

14．The same goes for "crash diets" that some companies say will make us lose weight fast.

　①go在本句中意为"行得通，起作用"。再如：

　　This truth goes everywhere. 这个真理到处适用。

　go也可意为"流传；表达"。如：

As the saying goes, a bird in the hand is worth two in the bush. 俗话说，双鸟在林不如一鸟在手。

　②some companies say是定语从句中的插入语，这种插入语应位于关系代词之后。如：

　　Choose the one answer which you think is correct in the following.

15．We ought to learn more about our body and the fuel it needs to keep fit. Only in that way will we be ready for the challenges and opportunities in life.

　①it needs是定语从句，修饰fuel；so that引起目的状语从句。

②be well prepared for=be ready for意为"为......做好充分准备"，表示一种状态，be若换成get则表示动作，不延续。如：