When Huawei P20 came out,         people couldn't wait to buy one in our town.

thousand

thousands

thousand of

thousands of

考查数词的用法。句意：当华为P20上市时，成千上万的人迫不及待的想在我们镇上买一台。thousnad意思是“千”，其前有具体数词修饰时，用其单数形式；当其前没有具体数词修饰时，用其复数形式，且与of 连用，thousands of“成千上万的”，这里没有具体数词修饰。故选D项。

When            to someone,I usually say, "Pleased to meet you."

introduce

introduced

introducing

am introduced

考查过去分词和省略。句意：当我被介绍给别人时，我通常会说：“很高兴认识你”。根据句子结构可知，本句是when引导的时间状语从句，原句when I am introduced to someone,这里当从句主语与主句主语一致时，并且从句的谓语动词有be这时从句的主语与be同时省略，所以空格处introduced。故选B项。

— Is it my age ________the boss minds?
—I’m afraid so. He will consider ________ necessary to have an experienced assistant.

which；it

that；it

which；that

that；that

考查强调句型和it的用法。第一空that与it is构成强调句型。第二空it是一个形式宾语，真正的宾语是不定式to have an experienced assistant，选B。

It was not until 1920 ___ regular radio broadcasts began.

when

which

that

since

此题考查强调句。句意为：直到1920年，常规的电台才开始。这句话把it is/was和that去掉后，仍是完整的一句话，因此我们可以知道这是一个强调句，而且是对not...until“直到...才”的强调。结构是：it is/was+not until+其他成分。故选:C.

---Let me help you cross the street.

---               ! I'm not that old.

Come on

No way

Take your time

Go ahead

考查情景交际。句意：---我来帮你过马路。---拜托。我还没有那么老。A. come on 可以表示鼓励，催促，加油，不耐烦等；B.No way 绝不；C. Take your time 别着急；D. Go ahead 表同意，继续。根据句意，选go ahead,可译为“拜托”。故选A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。

If you don't understand something, you may resrarch, study, and talk to other people          you figure it out.

because

though

until

since

考查连词。句意：如果遇到不懂的东西，你可以搜索、研究，和别人交流直到弄明白。A. 因为； B. 尽管；C.until直到；D.since自从，因为。根据句意可知，until符合语境。故选C项。