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。

You must have had some moments when you were disappointed. If so, how           you deal with them?

will

did

can

do

考查动词的时态和语态。句意：你一定有过失望的时候。如果有，你是怎么处理的？must have done 表示对过去的事情的推测。可知时态为一般过去时。在特殊疑问句中助动词应用did。故选B项。

Dr.Rowan,           secretary resigned two weeks ago, has had to do all his own typing.

whose

of whom 

of which

which

考查定语从句。句意：罗文博士的秘书两周前辞职了，他只能自己打字。          secretary resigned two weeks ago是非限制性定语从句，修饰Dr.Rowan, 引导词在从句中作定语，表示“Dr.Rowan's”，表示“......的”，应用关系代词whose引导该从句。故选A项。

Small sailboats can easily turn over in the water ________.

if not managed carefully

if are not managed carefully

unless not managed carefully

unless are not managed carefully

---what shall we do tonight then?

---              whatever you want.

Help yourself

No problem

It's a deal

It's up to you

考查交际用语。句意：---我们今晚做什么。---由你决定，你想干什么都行。根据空格后的 whatever you want，以及句意可知空格处填It's up to you由你定。故选D项。

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。