1.amateur astronomers 业余天文学家

例句:I would again encourage all interested amateur astronomers to new attempts in this direction.

我要鼓励所有感兴趣的业余天文学家在这方面做出新尝试。

2.take place 发生；举行

例句:Elections were postponed the day before polling was due to take place.

在预定进行投票的前一天选举被延期。

3.at the time 那时；当时

例句:I was not in Britain at the time.

当时我不在英国。

4.set out 出发；开始

例句:When setting out on a long walk, always wear suitable boots.

每次出发远行，都要穿合适的鞋子。