Glaciers can only form when

a.

there is an ice age.

b.

there is a u-shaped valley in the mountains.

c.

the amount of snow exceeds the amount of rain.

d.

more snow falls than melts.

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

How are 3-d printers useful in studying evolution? a. to color the fossils of organisms b. to create clones of extinct organisms c. to create replicas of fossils d. to prepare paper cutouts of organisms e. to study the composition of fossils

El año pasado fuimos a guatemala y nos en el hotel amanecer.