in spare time还是at spare time（on holiday与in holiday区别）

是in spare time

In spare time, I also read newspapers.

在空闲时，我也会阅读报

Plant Vegetables in Spare Time During Work?

在工作之余种种小菜？

In spare time, of course he'd like to see Statue of Liberty.

工作之余，当然要看看自由女神像。

Choose ea job you love and have your own hobbies in spare time.

选择一份自己喜欢的工作，并有自己的业余爱好。

Taking part time jobs in spare time can enrich one's experience.

在闲暇时间做兼职可以丰富一个人的经历。