at times:
有時(shí)；不時(shí)
[例句]
The tide is,at times,very high.
潮水有時(shí)漲得很高.
I like Bob but he's very annoying at times.
我喜歡鮑勃,但是他有時(shí)也很煩人.
at a time
作“一次,每次”講,常用于“數(shù)詞+at a time”的結(jié)構(gòu)中.例如：
Enter two at a time.
每次進(jìn)來兩人.
He checked them off one at a time as they came in.
他們進(jìn)來時(shí),他一個(gè)一個(gè)地核對(duì).
注意它與at one time 的區(qū)別.at one time一般指“過去某一時(shí)期,曾一度(once)”或“同時(shí)”的意思.如表示“同時(shí)”,則兩者可通用.例如：
At one time I used to like her,but not any more.
我曾一度很喜歡他,現(xiàn)在可不喜歡了.
in a time 和on a time 都是在一個(gè)時(shí)間的意思,另外還有2個(gè)短語(yǔ)需要也很重要in time和on time
in time
(1) Before a time limit expires.
及時(shí)：在時(shí)限到來之前
(2) Within an indefinite time; eventually:
最后,終于：在不定的時(shí)間內(nèi)；最終：
In time they came to accept the harsh facts.
他們最終承認(rèn)了嚴(yán)酷的事實(shí)
on time
(1) According to schedule; punctual or punctually.
按時(shí),準(zhǔn)時(shí)：按時(shí)間表的；準(zhǔn)時(shí)的（地）
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