4
A basic rule or law of science.
7
To put a new thing or person in place of an old one.
8
To bring in and hold a substance such as water.
9
The reason that something exists.
10
The art of planning how to make something new.
11
Can be used to help you in some way.
12
Path in a road marked by yellow or white lines.
13
To let something happen; to permit.
14
Activity or piece of work that needs to be done.
