Question

Every man, woman, and child _____ a flag. which verb form correctly completes the sentence? were waving be waving was waving

Answer 1

Was waving

You can say it like:
"Every man was waving a flag"
"Every woman was waving a flag"
"Every child was waving a flag"

It also makes sense to say it in present tense
"Every man is waving a flag"
"Every woman is waving a flag"

It wouldn't make sense to say:
"Every man are waving a flag"
"Every man be waving a flag"

Answer 2

The answer is C: was waving. Every is a determiner and one of its purposes is to refer to all members of a group of three or more, but they are considered individually. Altought this word represents more thant one, still it takes a singular verb. Other examples are: Every worker knows the machine. Everybody likes parties. Every student has a schedule.