Question

1) Materials that easily catch fire
2) Superior mental acuteness

3)A person who always expects the worst to happen
4) A person who is a hundred or more years old
5) Speech delivered without any preparation
6) The original inhabitants of a country
7) A place where many birds are kept
8) That which cannot be understood
9) Moving to and fro
10) A person who teaches university students​

Answer 1

Answer:

1) Materials that easily catch fire- Cotton, linen and viscose. Cellulose fibres, like cotton, linen and viscose, easily catch fire.

2)Superior mental acuteness-acumen

3)A person who always expects the worst to happen- pessimistic

4)A person who is a hundred or more years old- centenarian

5)Speech delivered without any preparation- extempore

6)The original inhabitants of a country- aborigines

7)A place where many birds are kept- aviary

8)That which cannot be understood- unfathomable

9)Moving to and fro- back-forth

10)A person who teaches university students​- professor