How does the presence of permafrost affect tundra plant life? A. It prevents all roots from growing, so only lichens can grow.
B. It provides moisture for roots to grow deep, allowing many types of plant life.
c. It only allows shallow root growth, so large plants cannot grow as they normally would.
D. It leaches minerals from the top layer of soil, preventing most plants from growing.

Group control group #1 experimental group yes yes yes control group #2 no new drug orange juice bed rest no yes no yes ves which of the following is the best explanation of why a second control group was included in this experiment? o a. to provide the volunteers in the study with something to drink o b. to prove that the common cold cannot be cured c. to confuse anyone who is trying to steal their new drug and sell it as their own invention o d. to researchers conclude that results are related to the new drug and not to the orange juice submit e previous