For question 1 the correct answer is:
B. Open and honest communication contribute to a happy relationship.
the subject Open and honest communication is plural then the verb agrees to it
For question 2 the correct answer is:
D. Interesting news<u> is</u> what sells our paper.
the subject Interesting news is singular, so the congujation of the verb BE "is" is the correct one.
Assure could mean making sure something happens, to comfort or remove doubts from a person, or make someone sure of something.
If it's one word answers it could be persuading, guaranteeing, promising, convincing, reassure, satisfy, or tell.
I hope this helps without answer choices it's kind of hard to know what kind of answer you need. Have a great day!
Answer:
I think the answer is Mayas made striking advances in writing, astronomy, and architecture, the Aztecs adapted earlier pyramid designs to build massive stone temples, and the Incas showed great skill in engineering and in managing their huge empire
