Which landform is created by flowing water?

.Cirques
.Gullies
.Horns
.Dunes

Cassandra made a venn diagram to compare and contrast the two stages of cellular respiration. which belongs in the area marked x? energy is released. oxygen is used up. glucose is broken down. carbon dioxide is used up.

Jason adds the antibiotic penicillin to a bacterial culture. the bacteria develop genetic modifications in their genome, which gives them resistance to the antibiotic penicillin. what caused this genetic modification?

Ialready know the answers to these questions and they are on the attachment. but i just need to know why that answer is the correct one. plz asap! this is for a report that i need to email by 10!