sparetime前面加什麼介詞

前面加介詞in，例如：

1、He's studying music in his spare time.他在空閒時間學音樂。

2、Besides working as a doctor， he also writes novels in his spare time.除了當醫生之外，他在業餘時間還寫小説。

3、In her spare time she does voluntary work她在業餘時間做義工。