Unit 4 Creatures large and small Module 2

Grammar

1. 现在分词是由 “ 动词 +ing” 构成, 现在分词 具有动词的特征和形容词的功能. 既可以单 独使用, 也可与其他词一起构成分词短语. 2. 现在分词可以作名词的定语, 单独使用时, 现 在分词相当于一个形容词, 放在名词的 前面. 3. 当现在分词 带有状语时, 通常放在名词后 面作定语, 相当于定语从句的作用.

Scientists are trying to develop a material which has similar properties as spider silk. →Scientists are trying to develop a material which has similar properties as spider. →Scientists are trying to develop a material having similar properties as spider silk. 现在分词

A Present participle phrases after nouns A participle phrases can be used after nouns to identify them. Scientists are trying to develop a material having similar properties as spider silk. A participle phrases can often be replaced by a relative clause: Scientists are trying to develop a material which has similar properties as spider silk.

Combine each pair of sentences by using a present participle phrases. The first one has been done for you. 1.Some spiders do not build webs. These spiders are living in the desert. ______________________________ 2. They dig holes in the ground to find shelter. This shelter protects them from the heat. ______________________________ Some spiders living in the desert do not biuld webs. They dig holes in the ground to find shelter protecting them from the hear.

3. They wait in their holes for mice. These mice are walking by. ______________________________ 4. The spiders jump from their holes. The holes are hiding them. _______________________________ 5. The mice are injected with poison. The mice are being caught. ______________________________ 6. The spiders store the mice for later. The mice serve as a source of food. _______________________________ They wait in their holesfor mice walking by. The spiders jump from the holes hiding them. The mice being caught are injected with poison. The spiders store the mice serving as a source of food for later.

1. 现在分词短语可以作状语表示时间、方式、原因，它 的作用相当于一个状语从句。其逻辑主语应该与主句 主语一致。如： While (bears are) hibernating, bears stay in their dens. 2. 现在分词的一般式作状语时，动作发生的时间与主句 动词通常是同时或几乎同时进行。如果分词发生的动 作在主句谓语动词的动作之前，通常要用现在分词的 完成式。 3. 现在分词前面可以带有连词 when, whenever, while, once, until, if 和 although 。 4. 现在分词短语作状语表示方式时，通常跟在动词 stand, go, come 和 sit 后。 如： He stood learning against the wall.

Present participle phrases used as adverbials Participle phrases can be used as adverbials to express time, reason or manner. The subject of the participle phrases is often the same subject as in the main clause. Participle phrases as an adverbial of time. Surviving winter in these tents, the spiders emerge healthy and hungry when spring comes.

Participle phrases as an adverbial of time. Surviving winter in these tents, the spiders emerge healthy and hungry when spring comes.

Being stronger than steel and lighter than a feather, spider silk has many useful properties. Looking like they are dead, bate hang upside down in winter.

Note: Perfect participles (active: having done; passive: having been done) are often used to talk about the action that happens earlier than another action. This is a rather formal, written pattern. In spring, having awakened, bears leave their dens, thin and hungry. We can use a participle after conjunctions such as when, whenever, while, once, until, if and although. While hibernating, bears stay in their dens.

1.Bears find a place on the side of a hill. They dig dens in the autumn. (find) ______________________________________ ___________________________________ 2. Bears fill their dens with grass and leaves. They make a bed for themselves. (fill) ______________________________________ __________________________________ 3. Bears gain up to 20 kg a week during summer and autumn. They hibernate. (gain) ___________________________ Combine each pair of sentences using a participle and the words given in brackets. Make any other necessary changes. Having found a place on the side of a hill, bear dig dens in the autumn. Filling their dens with grass and leaves, bears make a bed for themselves. Having gained up to 20 kg a week during summer and autumn, bears hibernate.

4.Bears see first big snowfall. They enter their dens and fall asleep. (see) _____________________________________ ______________________________________ 5. Bears usually sleep. They do not eat or drink much during winter. (sleep) ______________________________________ _______________________________________ 6. The hungry bears abandon their dens in early spring. They immediately hunt for food. (abandon) ______________________________________ _______________________________________ Seeing the first big snowball, bears enter their dens and fall asleep. Usually sleeping, bears do not eat or drink much during winter. Abandoning their dens in early morning, the hungry bears immediately hunt for food.