How can i boost my score on reading section? and what are the good books for that also online sources

How many questions do they give on the sat

The authors use the word “backbone” in lines 3 and 39 to indicate that

Dna is a polymer of which consist of a sugar, a phosphate group, and a a. amino acids; nucleotide b. nucleic acids; nucleotide c. nucleotides; nitrogenous base d. nucleotides; nucleic acid e. proteins; nucleotide