二、学海导航
【学法指要】
本单元应掌握的难点知识：
⒈分词作定语
They invented different kinds of fishing nets, also a curiously shaped piece of wood for hunting which… (page 14)
他们发明了各种各样的渔网，还发明了一种用木头制成的形状奇特的捕猎器，……
在”a curiously shaped piece of wood”中的”shaped”是以动词”shape (vt.使成……形状)”的过去分词作定语。
分词作定语是一种重要的用法。在各种测试中常要求被测试者准确选用是现在分词还是过去分词。为此必须理解分词与被修饰的名词的语法关系。一般说来，当分词与被修饰的名词是主谓关系时用现在分词；当分词与被修饰的名词是动宾关系时用过去分词。如：the falling leaves (=the leaves that are falling);the surprising news (=the news that are surprising); the broken glass (=the glass that is broken); shaped piece of wood (=the piece of wood that is curiously shaped).
[注意]不及物动词的过去分词也可以作定语，表示完成或状态。如：the fallen leaves (=the leaves that are fallen)
⒉熟记表示倍数的句型: be…times as +adj./adv. (形容词或副词)+as…
be…times + adj./adv.(形容词或副词)+than…
be…times + the size of…
The newly-built reading-room is four times as big as the old one.
新建的阅览室是旧阅览室的四倍。
The newly-built reading-room is three times bigger than the old one.
新建的阅览室比旧阅览室大三倍。
The newly-built reading-room is four times the size of the old one.
新建的阅览室是旧阅览室的四倍。

【妙文赏析】
Kangaroos lives only in Australia and on the islands near it. Not many people knew they were there until about 200 years ago. At that time, Captain Cook sailed to Australia from England.
He and his men had traveled halfway around the world. They needed food
for the long trip home. Captain Cook sent a few sailors ashore to get food.
When the sailor returned, they brought with them a big grey animal. The men’s eyes were being opened wide.
“Look at his tail,” said one, “It must be four feet long!”
“What’s the animal called?” asked the captain.
“We tried to get the people to tell us,” answered a sailor, “They kept saying ’Kangaroo’. They wouldn’t say anything else.”
“Kangaroo,” said Captain Cook, “That’s a good name. It sounds as queer as he looks. Captain Cook carefully noted this word in his word book.”
The missionaries(传教士) who later came to Australia were anxious to see a kangaroo but their questions were met with puzzled looks. They soon discovered that the native who answered Cook’s question was really saying, “I don’t know what you’re pointing at.” This is how the word “Kangaroo” has come into use.

【思维体操】
非谓语动词作宾语补语时的混淆，出在感观动词与使役动词后接不定式与现在分词的差别，现在分词与过去分词的差别。除此之外，其外动词的用法都是固定的。
⒈在感观动词与使役动词后接不定式，表示强调动作本身已经发生，它指动作的全过程，因而表明该动作已结束。
⒉现在分词表明动作的情景，即动作正在进行，在使役动词后还含有让动作得以延续之意。
用所给动词的适当形式填空：
1)When I went into the hall, I found a group of children _____(run) upstairs.