1 to rescue someone or something from a bad situation
5 when something is required or expected
7 point beyond which it is not possible to go
8 to use your ears to hear and understand things
10 lowest part of the leg we use to stand on
11 more formal term for on
13 to confirm the details of something are correct
16 focus of your thoughts on something
18 use or knowledge of science in industry, engineering, etc.
19 substance from which a thing is made of