【解释】

cause：指造成一种影响、结果或后果的原因或条件。（与of连用）

excuse 强调为逃避或减轻责任而设法辩解而使用的借口，理由（与for连用）

reason 是指解释某种效果的发生或性质的措辞（与for连用） 【练习】选择cause/excuse 或reason，并用其适当的形式填空

1) There was no obvious ________ for the accident.

2) Sometimes most students will make up a(n) _________ for their absence.

3) The ________ she went to Guangzhou was the climate.

4) Carelessness is the ________ of his failure.

Keys: 1) reason 2) excuse 3)reason 4)cause 3) electric/electrical adj. 【解释】

electric 用于修饰需要用电来运转的设备或用于比喻"震惊"

electrical 常用于表示与电气性质或科学相关 【练习】选择electric或electrical 并用其适当的形式填空

1) Many _______ fans are required in such a large meeting room.

2) The room became ________ with amazement.

3) To be an ________ engineer is the dream of many boys.

Keys: 1) electric 2) electric 3) electrical 4). jewelry/jewel n. 【解释】

jewelry 珠宝, 珠宝类的总称[不可数名词]

jewel珠宝[可数名词] 【练习】选择jewelry或jewel并用其适当的形式填空

1) The ______ of the rich were often kept in the bank.

2) She locked her_________ in the _________ box.

Keys: 1) jewels 2) jewels; jewelry III 词性变化 （旨在提供语法填空所需材料）

bleed v. 使出血, 放血 blood n. 血, 血液, 血统 bloody adj. 有血的, mild adj. 温和的, 温柔的 mildly adv. 温和地, 适度地 treat v. 视为, 对待, 治疗 treatment n. 待遇, 对待, 处理, 治疗 pressure n. 压, 压力,压迫 press v. 压, 压迫 bravery n勇敢 brave n. 勇敢的 【练习】根据句子结构，用括号内所提供词的适当形式填空

1) A person of hot _______ is not afraid of _______ in battle for the country.(blood)

2) I was only ______ interested in English when I took up it.(mild)

3) people had to _____ themselves in their own way, before they received the ____ sent by the government.(treat)

4) ________ this button and the _______ of the water will rise.(press)

5) The ______ boys were rewarded with medals for their ________in Wenchan earthquake.

keys: 1) blood; bleeding 2) mildly 3) treat; treatment 4) Press; pressure 5) brave; bravery IV 重点词汇 （旨在提供综合运用所需材料）

1. aid n.&vt.帮助；援助；资助