▲at the beginning of
This huge triumphal arch was erected at the beginning of this century. 这座巨大的凯旋门是本世纪初建造的。
Many German artists fled toAmericaat the beginning of World War II. 第二次世界大战初期，许多德国艺术家逃往美国。
▲at the end of
A lot of people need a tonic at the end of the winter. 很多人冬末需要进补。
Cycling enjoyed a vogue at the end of the nineteenth century. 19 世纪末骑自行车曾风行一时。
At the end of the afternoon they were exhausted and half asleep. 傍晚时分他们都筋疲力尽，昏昏欲睡。
▲at Easter
They always go to church at Easter. 他们在复活节时总是去做礼拜。
They usually have a walking holiday at Easter. 复活节假期他们通常都会去徒步旅行。
The kids get two weeks off school at Easter. 复活节期间孩子们可以有两个星期的假不用上学。
▲at Christmas
The Bradfords always entertained lavishly at Christmas. 布拉德福德夫妇在圣诞节总是盛情地款待大家。
Having to cook for everyone at Christmas put his mother in a real flap. 得在圣诞节给所有人做饭，这使他妈妈很是着急。
All the children and grandchildren are going to my parents’ at Christmas for the annual gathering of the clan. 儿孙们圣诞节都要到我父母家参加一年一度的家族聚会。
▲at New Year
You had a holiday at Christmas, at New Year and at Easter. 你在圣诞节、新年和复活节都休了假。
▲at lunchtime
Who’s going to man the stall at lunchtime? 午饭时谁来看摊？
A catnap at lunchtime can make you feel refreshed. 午间小睡可以使你精神起来。
Many restaurants do a very reasonable set menu at lunchtime. 许多餐馆中午都提供价钱合理的客饭。
▲at night
She doesn’t wear her dentures at night. 她晚上不戴托牙。
Stray dogs roamed the streets at night. 流浪狗晚上在街上游荡。
Not eating late at night should help to relieve the discomfort. 深夜不进食应有助于减轻不适。
Not being able to sleep at night is a very common complaint. 晚上睡不好觉是很常见的毛病。
▲at regular intervals
He comes back to see us at regular intervals. 他每隔一段时间就回来看看我们。
The phone rang at regular intervals all afternoon. 整个下午每隔一定时间电话铃就响一次。
Trains will run at regular intervals from 11am to 4pm. 火车从上午 11 点到下午 4 点每隔一定时间开行。
▲at puberty 与 during puberty 均表示“在青春期（期间）”，但比较而言，用 during 时，更强调“期间”的意味。