Question

Given a template strand of 3' ATGCTTGGACA 5' and partially made complementary strand containing only 5' TAC 3', what would be the sequence of the new strand of DNA (including the 5' TAC 3') if the only additional nucleotides available to DNA polymerase were those containing the bases G, A, and C?

Answer 1

The enzyme DNA polymerase will  form hydrogen bonds with the nucleotides of the template DNA and add new nucleotides, adenine will bond with thymine and guanine will bond with cytosine, forming the complementary strand.

3' ATGCTTGGACA 5 is the DNA template
5' TACGAACC .......3' is the complementary strand
you just need to join the right nucleotides. If there is no T, the DNA polymerase has nothing appropriate to connect to the A, so it stops there