I think it's Photosynthesis because photosynthetic bacteria began producing excess oxygen, which added oxygen to the Earth's atmosphere.
Answer:
Ethical concerns about the development and use of biotechnology include all of the following except <em><u>concern about the development of new weapons.</u></em>
Thymine goes with adenine
Gaunine goes with cytosine
I always remember A and T spells “at” ...
Answer:
C.were formed at the same time.
Explanation:
If the same index fossils occurred in two separate rock layers, the two rock layers would probably have been established at the same time. Index fossils aid the characterizing and classify of geologic period.
Answer:
I would probably say that it was most different because of the cars. The first car was released in 1885, but they weren't really popularized in America until the 1920s. So therefore, Earth's atmosphere was much better than it is now.
