表示时间：
time in 1999， in 20 century， in a flash(瞬时)，
in a lucky hour(在幸运时刻)， in a minute， in a second，
in a short time， in a while， in a wink(一瞬间)
in advance(预先)， in an emergency(在紧急地时候)，
in an evil hour(在不幸地时刻)， in an instant， in ancient times，
in broad day(在大白天)， in course of， (在…期间)，
in December， in due course(及时地)， in future，
in good season(及时地)， in no time(马上)，
in one‘s childhood， in one‘s spare time，
in one‘s teens， in one‘s youth，
in recent years， in season(适时)， in seconds(在很短的时间)，
in some cases(有时候)， in spring， in the afternoon，
in the beginning， in the daytime， in the end，
in the evening， in the future， in the long run(最后)，
in the meantime， in the morning， in the nick of time(在紧急关头)，
in the night， in the past， in the thick of (在最激烈的时刻)，
in the thick of(在最激烈的时刻)， in this period， in those days， in time of war， in time，
on on a certain day， on a sudden(突然)，
on a winter morning， on Christmas Day， on night shift， on one‘s birthday， on schedule(按时)，
on Sunday， on that date， on the eve of， on the following day， on the instant(马上)，
on the moment(立刻)，
on the Monday morning， on the New Year‘s Eve， on the next morning， on the point of(正在…时候)，
on the spur of the moment(立刻) on this day， on this occasion， on time，
at at a time(在某时)，
at a wedding(婚礼)，
at all times(一直)， at any moment， at any time， at Christmas，
at dark (天黑时)， at dawn(在黎明)， at daybreak， at dinner-time，
at dusk(在黄昏)， at Easter， at first sight，(一见到)，
at first， at last， at midnight， at night， at nightfall， at noon， at present， at six clock， at sunrise， at sunset，
at that moment， at that time， at the age of， at the beginning of ， at the correct time，
at the end of， at the last minute， at the moment，
at the present stage at the same time， at the stage(眼下) at the start， at the time being，
at the time of， at the very start， at this point(此时)， at this season，
at this time of day， at times(有时)
