1 cave

2 hole

3 zero (unambiguous spoken form when spelling out numbers)

4 classifier: 个 gè

1 to be familiar with

2 to know well

1 cavern

2 cave

1 Sydney, capital of New South Wales, Australia

1 to put one's heart (and soul) into sth

2 with great care

1 A small hole not plugged will make you suffer a big hole (idiom); A stitch in time saves nine.

1 a small hole not plugged will give you grief when it gets bigger (idiom)

2 a stitch in time saves nine

1 If you don't plug the small hole, the big hole will be hard to repair (idiom); A stitch in time saves nine.

1 A small hole not plugged will make you suffer a big hole (idiom); a stitch in time saves nine

1 lit. to pull a snake from its hole

2 to expose a malefactor (idiom)