【解释】

let允许，让，常用于口语中，一般不用于被动语态。后接不带to的不定式作宾补。

permit和allow意思相近，都表示"允许，准许"。permit稍正式一些，多指上级对下级或长辈对晚辈的准许,语气较强；allow多指听任或不管教某人做某事。

常用句型allow/permit sb. to do sth. be allowed/permitted to do sth. allow/permit doing sth. 【练习】根据句子意思用permit，allow或所给词的适当形式填空。

1). Students are not _________ to enter the Net Bar.

2). My mother wouldn' t let me _______ (go) to the film.

3). We don' t allow _______ (smoke) in our office.

4). Weather _______ (permit), we' ll go outing this weekend.

Keys: 1). allowed/permitted 2). go 3). smoking 4). permitting 3. scream / shout 【解释】

scream指因痛苦、恐惧、激动或生气而喊叫、尖叫，声音大而尖利，常与to连用

shout指因愤怒或为引起注意而发出的声音，大喊，大叫，大声说话，常常与at连用 【练习】根据句子意思用scream，shout的适当形式填空。

1). There was a huge bang and people started _______.

2). Two women were _______ at each other outside the supermarket.

3). I had to _______ to make myself heard.

4). The fans _______ with excitement when they saw him.

Keys: 1). screaming 2). shouting 3). shout 4). screamed

Ⅱ. 词性变化（旨在提供语法填空所需材料）

1. believe vt.&vi.相信；认为 belief n. 相信，信念，信仰 believable adj.可相信的 unbelievable adj.难以置信的 2. survive vi.幸存，继续存在 vt.幸免于；挺过来 survival n.幸存，幸存者，残存物 survivor n.未死的人；残存者 3. permit v. 允许

n.许可证，执照 permission n. 允许，许

可，准许