Why do plants not have a exsited before cyanobacteria started producing oxygen?

When a new branch containing a resistor is added to a parallel circuit, the total circuit resistance:?

All animals need oxygen. We get oxygen from the air we breathe. How do fish get theirs?

Choose all the answers that apply. Which of the following are ways to reduce wind erosion? A). plant trees B). cut down trees C). create windbreaks D). irrigate dry fields E). remove dead leaves

A 747 jetliner lands and begins to slow to a stop as it moves along the runway. If its mass is 3.5 x 10 exponent 5 kg, its speed is 27.0 m/s and the net braking force is 4.30 x 10 exponent 5 N, (A) what id its speed 7.

A car driving on the turnpike accelerates uniformly in the positive x direction from 80 ft/s (54.5 mph) to 103 ft/s (70.2 mph) in 3.10s. What is the x - component of the car's acceleration?

A derived unit is a combination of fundamental units. Which of the following is an example of a derived unit? a) centimeter (used to measure distance) b) gram (used to measure mass) c) cubic centimeter (used to measure volume)

Technician A says that a heater core leak can be the result of the coolant wearing a hole through the core. Technician B says that a core leak can be caused by chemical action eating a hole through the core. Who is correct?

If the Coast Guard warns of a giant wave of water approaching the shore as a result of a major earthquake, they are warning of a. an aftershock. b. liquefaction. c. a tsunami. d. landslides.

What is the total number of atoms in the following formula? CaBr2 4 3 2 1

Object A with a mass of 500 kilograms hits stationary object B with a mass of 920 kilograms. If the collision is elastic, what happens after the collision? A) Both object A and object B move forward but with different velocities.