Using the rules for selecting symbols for the elements, which of the following could NOT be a correct symbol for a chemical element?

1.A
2.Ch
3.CA
4.Сс

Creation of an unnaturally uniform sample to represent a diverse populationcan be avoided by: a. including only willing b. asking another scientist for .c. choosing only identical participants. d. selecting individuals at random.

Idon’t know the answer and i’ve been stuck on it for a while now skskskskks

In a vegetable garden 45 bean plants have been eaten by deer 5 are untouched what is the frequency of bean plants in the garden that have been eaten?