What must happen for a solar eclipse to occur?

A) The moon must be full.

B) The moon must pass behind Earth.

C) The moon's orbit must cross the plane of the ecliptic.

D) The moon's orbit must not cross Earth's penumbra.

What compound is the human body unable to synthesize, but is essential in lowering blood pressure and blood levels of harmful lipids?

If a reaction in one direction releases energy, the reaction in the opposite direction a destroys energy. b also releases energy. c absorbs energy. d cannot occur.

Take two glasses, fill one with water and leave the other empty. Place them side by side. Fold a paper towel lengthwise and put one end into the water in the glass with water. Stick the other end of the paper towel in the empty glass.

Interaction: lungs supply oxygen carried by blood to cells of the body

What is the most likely effect a decrease of plant life in the biosphere would have on the atmosphere? a. A decrease in plant life would have no effect on the atmosphere. b.

Can energy be transferred from animal to animal

The more stomata the more water loss?

Why does it take a long time to develop a new variety of tomato? A. Changes in traits happen gradually, over many generations. B. Many plants resist change. C. Tomatoes cannot acquire new traits. D. A species cannot change over time.

Select the one true statement. Vacuoles store nutrients, water, and waste in animal cells. Plant cells can have chloroplasts but do not have a cell wall.

Using water more effectively A. Protects the environment B. Causes the loss of natural pollution filters C. Increases with contamination D. All of the above