9 Though Mrs Bussman was fully acquainted with this story

acquaint v. 使了解

be acquainted with sth. 对......有所了解

acquaint sb. with sth. / acquaint sb. of sth. 告之某人某事

make a person acquainted with sb. 介绍某人同另一个人认识

Let me make ... acquainted with you (正式用法)

acquaintance n. 熟人

10 Hans returned to his family home, but the house had been bombed and no one in the neighbouthood knew what had become of the inhabitants

become of ==happen to 发生遭遇，不幸的事件，多用于疑问句，主语必须是what / whatever新概念作文在线阅读

Eg: Whatever became of that girl?

Please explain what became of you yesterday.

11 used to & would

used to & would 都可表示过去的习惯, 且现在此习惯已不存在.

Eg:  I used to smoke, but I don't any more.

I would narmally spend the winter in Miami.

used to 可以用来描述过去的状态, 但是would 不行

Eg: I'm not quite as sure as I used to be.

used to 仅用于一般过去时