How has human land use impacted the environment

In what year did the US and several other nations agree to reduce the quantity of CFCs used by 50%? 2017 1987 2007 1997

How do the properties and location of callisto differ from those of the other galilean moons?

Use this partial DNA sequence (the original sequence with no mutations) to answer the following questions.

How are the scale like parts of hair formed?

Pepsin is produced by cells lining the stomach. It catalyzes reactions needed to digest certain proteins. After leaving the stomach, food enters the small intestine. The pH of the small intestine is around 7.

What are two ways that humans pollute the air?

How does the water inside plants return to the atmosphere? Runoff Evaporation Precipitation Transpiration

Mitosis results in how many cells? are they different or identical? what kind of cells do mitosis?

Dense water near the poles sinks, creating a current towards the equator. What would you expect to happen to the current if temperatures at the poles decreased?

Which substance will have a pH close to 7