内容正文:
2019年11月5日
be able to & promise
中考频度:★★★☆☆ 难易程度:★★★☆☆
1.(2019﹒湖北武汉市)At first, everything was___21(perfect)___:I had so much work that I had to take on an assistant(助理),my best friend at work, Don, just to be___22___to finish things on time.
A. afraid
B. ready
C. able
D. about
【答案】C
【解析】句意:起初,一切都非常好:我有如此多的工作以至于我不得不雇佣我的好朋友唐作为助理来工作,这样仅仅能按时完成工作"。本题考查形容词辨析。A.害怕的;B.准备好的;C.能;D.大约。根据句意可知,我雇佣了一个助理,这样仅仅能按时完成任务。be able to能,故选C。
【归纳拓展】
be able to
be able to表示"能够",相当于 can,常用来表示 can不能表达的将来时或完成时的情况,可用于各种时态。
He will be able to finish reading the book next week.
他下周将能读完这本书。
【易混辨析】
can / be able to
(1) can"能",表示过去或现在"能力所及"时,与be able to 通用。
He can / is able to speak German. 他会说德语。
I could / was able to run very fast when I was a boy. 我小时候就跑得很快。
(2) be able to的过去式还可表示一种"经过努力做到了"的意思。而can的过去式则没有这种意义。
He started late, but he was able to catch the train.
他出发晚了,但他还是赶上了火车。
(3) can通常只用于过去或现在两种时态,而be able to 则可用于各种时态。
He has not been able to come since he got hurt.
自从受伤以后,他就一直未能前来。
(4)在表示猜测时,只能用can,而不能用b