他闻了闻他的袜子，看看是否需要清洗。

He ___sniffed his socks to see if they needed to be washed.

狗喜欢互相嗅闻。

Dogs love ___sniffing each other.

杰克用手指碾碎新鲜香草并闻了闻。

Jack crushed the fresh herbs between his fingers and ___sniffed.