第二次世界大战发生在20世纪40年代。

World War II took place in the ___1940s.

他在40多岁时开始学习弹钢琴。

He started learning to play the piano in his ___40s.

春天，白天气温通常在40多华氏度左右。

In spring, the daytime temperature usually stays in the ___40s.