Which sources are reliable? check all that apply.

a. an article discussing mineral resources written by the united states geological survey
b. a blog discussing sources of alternate energy written by a high school student
an advertisement for guided hikes and tours in camping magazine
c. a study describing clinical trials of a new medication in the journal of medicinal chemistry
d. an entry about common uses of metals in an encyclopedia that can be edited by the general public

The correct answer will be options-A and C.

Explanation:

The research on any question starts with a "review of literature study" which helps gain the knowledge related to the aspect of the hypothesis one is studying.

The sources reviewed by the researcher must follow certain criteria to be cited like:

1. The research should be done by any governmental organisation, research institutes and affiliated universities.

2. The research paper should posses results checked and verified by the peer fellows like by the peer-review of journals.

3. The research should not be edited any general magazines, advertisements and any other unauthorized organizations.

Thus, option-A and C are the correct answer.

a sequence is a function whose domain is the set of natural numbers.

natural numbers are all the negative and positive integers

the answer is a. co2, this would be colder than the : )

explanation: