What is the main function of signal words? A. They help readers predict the main ideas.
B. They suggest that the author is not an expert.
C. They alert the reader that the article is about to end.
D. They indicate that information is from a reliable source.

C

Explanation: They alert the reader that the article is about to end. Signal words or transition words are used by the author to connect ideas. There are different connections between ideas. Signal words show emphasis, addition, contrast, comparison, cause and effect, and sequence among others.

Okay, biology isn't exactly my strongest subject (it never has been), but i'm pretty sure the answer is nucleotides. dna is made up of nucleotides. each nucleotide contains a phosphate group, a sugar group, and a nitrogen base. there are four different nitrogen bases: adenine (a), thymine (t), guanine (g), and cytosine (c). a always pairs with t, and g always pairs with c.