Tom looks so pale today. He ______ ill.

must be

had to be

should be

shall be

[翻译]汤姆看起来脸色不好，他一定生病了。[解析] A 试题解析：情态动词must表示推测。题目中表示肯定的推测。

My little sister          me into buying this book.

wanted

advised

persuaded

told

考查动词词义辨析。句意：我的小妹妹说服我买了这本书。A. want想，想要；B.advised 建议；C. persuaded说服，劝服；D.told告诉。want  sb to do sth想要某人做某事；advise sb to do sth 建议某人做某事；persuade sb into doing sth 劝服某人做某事；tell sb to do sth告诉某人做某事。故选C项。

Her father         a writer.

turned

grew

has turned

has become

考查系动词的区别。句意：她的父亲变成了一位作家。Turn，grow，become用作系动词均可表示“变化”，使用时要注意：become主要指一个人暂时性的身心变化或永久性的自然变化，另外还可用于指天气变化和社会的趋势；grow主要表示逐渐变化，强度变化过程；turn后接名词，往往表示意想不到的变化，名词前通常不加冠词。故选D项。

I drink a cup of coffee           ; but usually I take tea.

frequently

often

constantly

occasionally

考查副词词义辨析。句意：我偶尔喝一杯咖啡，但我通常喝茶。A. frequently频繁地；B.often经常地；C.constantly连续不断地；D.occasionally偶尔地。but 表转折关系；根据后半句的usually,前面用occasionally,与usually意思相对。故选D项。

It is six months         the online class started.

that

until

before

since

考查固定句型。句意：在线课程已经开始六个月了。A. that 那，那个；B. until直到..... 为止；C. before在.....之前；D. since自.....以来。分析句子可知，句中涉及固定句型“ It is +一段时间+since引导的时间状语从句”，意为“自从......以来已经有多长时间了”，since从句中用非延续性动词。故选D项。

We cannot           the punctual arrival of trains in foggy weather.

get

help

guarantee

guess

考察动词词义辨析。句意：我们不能保证火车在雾天准时到达。A. get得到，获得；B. help 帮助；C. guarantee保证；D. guess猜测。根据句意可知，火车无法保证按时到达。故选C项。