Which statements about freshwater sources are true? Check all that apply. Only about 3 percent of Earth's water is fresh water.
Most of the fresh water on Earth is groundwater.
About 75 percent of the fresh water on Earth is frozen in ice sheets.
The largest source of usable fresh water is groundwater.
More fresh water is in the atmosphere than in rivers and lakes.

Imagine that you have produced several versions of lactase, each of which differs from normal lactase by a single amino acid. describe a test that could indirectly determine which of the versions significantly alters the three-dimensional shape of the lactase protein.

How does a catalyst increase the speed of a reaction? a. the catalyst eliminates the activated complex stage, allowing products to form immediately. b. the catalyst lowers the energy level of the reactants, making it easier for them to react. c. the catalyst makes it easier for the activated complex to form, lowering the activation energy. d. the catalyst raises the energy level of the products, making the reaction finish sooner. reset next

Which one of the following substances would be the most soluble in ccl4? na2so4 h2o ch3ch2ch2ch2oh c4h10 hi