The newly installed alarm system, which is directly connected to the police, will go off if the correct security code is not entered__________ 60 seconds of touching the keypad.

A．only

B．under

C．within

D．directly

查看答案及解析进入在线模考

参考答案

答案解析

【答案】C。解析：备选答案为副词和介词。首先应分析句子结构，判断横线处应填入介词还是副词。乍一看应填入副词修饰被动结构“is not entered”，实际上if从句是被动语态，“________60 seconds of touching the keypad”应作状语。因此横线处应填入介词，从而构成介宾短语作状语。

你可能感兴趣的试题

1 The airline requested a__________call to ensure a seat on my flight back home.

A．confirm

B．confirmed

C．confirming

D．confirmation

查看解析在线模考

2 If the task is too complicated to figure out on__________ own, please don't hesitate to ask one of our representatives, who are here to help.

A．you

B．your

C．yours

D．yourself

查看解析在线模考

3 The hard work put in during his younger years made him become __________sound in his later years.

A．finance

B．finances

C．financial

D．financially

查看解析在线模考