How long has there been life on Earth?

4.6 billion years
3.7 billion years
65 million years
3 million years

Layers of rock containing fossils, like the layers illustrated here, are most likely composed of rocks.

Which statement best describes the relationship between period and frequency of light waves? a) in wave b the period increases and the frequency decreases from wave a. b) in wave a the period increases and the frequency decreases from wave b. c) in wave b the period is shorter and the frequency is greater than in wave a. d) in wave a the period is shorter and the frequency is greater than in wave b.

Modern weaponry has increased the number of deaths in wars and violent conflicts.