2- Scientists do different experiments to, animal's intelligence.
b. measure
c. weigh
d. add
a. count​

b. measure

Explanation:

An experiment can be defined as an investigation which typically involves the process of manipulating an independent variable (the cause) in order to be able to determine or measure the dependent variable (the effect).

Hence, an experiment can show how changing a variable can affect behavior.

This ultimately implies that, an experiment can be used by scientists to show or demonstrate how a condition causes or gives rise to another i.e cause and effect, influence, behavior, etc in a sample.

Simply stated, the main purpose or essence of an experiment is to measure the variables involved.

Hence, scientists do different experiments to measure animal's intelligence.

ich statement best shows a problem in travels with charley?

one sharp difficulty presented itself. in the intervening twenty-five years my name had become reasonably well known.

this being so, my trip demanded that i leave my name and my identity at home.

i had to go alone and i had to be self-contained, a kind of casual turtle carrying his house on his back.

with all this in mind i wrote to the head office of a great corporation which manufactures trucks.

he has become more humble and patient in battle.