The fault lay, in many cases, with the emigrants themselves. they acted injudiciously. their fears caused them to drive too fast, in order to get over quickly. their animals were too weak to be urged in this way. a. annoyed b. formal c. fearful d. grateful

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.