11. People would pick up handfuls of gravel from the bottom of the streams and sort out the diamonds.

-ful通常加在名詞后面，構成形容詞，如care-careful，help-helpful.而本句中的handful是一個名詞，意思是“一把”，在單詞部分，我們已經提到過，英語中有不少這樣的詞，如：

1) He gave me a basketful of beaches. (他給了我滿滿一籃子桃子。)

2) She put a spoonful of salt in the soup. (她往湯里撒了滿滿一勺鹽。)

3) Tom is carrying an armful of books. (湯姆抱著一捆書。)

sort out是一個常用詞組，意思是“整理，分類”

bottom在句子中做名詞用，意思是“底部”。bottom還有“盡頭、末端”的意思

12. These diamonds were probably carried from where they were formed to India by great sheets of moving ice that covered parts of the earth 20，000 years ago.

where they were formed是where引出的名詞性從句，作介詞from的賓語。請看下面的句子：

He didn't say anything about where the accident took place. (他對事故在哪兒發生的只字未提。)

13. It flows over boards thickly coated with grease.

在本句中的定語從句thickly coated with greases前面省略了which/that are.coat一般做名詞用，意思是“外套”或“(動物的)皮毛”。在本句中coat作動詞用，意思是“在…上涂(包)著”，

14. Since diamonds stick to grease， they are left behind by the rocks and mud which flow down the tables.

Stick在本句中的意思是“粘住”。Stick to也可以表示“堅持，遵守”的意思。

leave behind在本句中的意思是“留下”，這個詞組還可以表示“忘帶;把…丟在后面”。例如：

1) Take care not to leave anything behind. (小心別丟下任何東西。)

2) Look forward to the bright future and leave all your worries and fears behind. (期盼光明的未來，把所有的擔心和恐懼拋在身后。)

15. Experienced diamond miners can tell a diamond immediately.

句子中的tell意思為“判斷;分辨;看出”。如：

I cannot tell her from her twin sister. (我無法分辨出她和她的孿生妹妹。)

Text B The Difference between Plants and Animals