幸好我们带了伞。

___It ___'s ___a ___good ___thing we brought our umbrellas.

年轻人在社交媒体上找到自己的发声方式是件好事。

___It ___'s ___a ___good ___thing that young people are finding their voice on social media.

幸好他及时赶到了。

___It ___'s ___a ___good ___thing he arrived when he did.