A student wants to determine how his classmates feel about school. He does a survey away from school so all participants will be willing to answer freely. In several cases, younger siblings of his classmates are
present, so he lets them take the survey too. He surveys a total of 50 students. Has he done a well-
designed, controlled experiment? Select the correct answer.

The answer is c establishing proper sleep hygiene

By water evaporation from the leaves is created a negative pressure at the top of the tree that promotes the ascension  of the water through channels that are called xylem. there are also two molecule forces that are involved: the intra-water molecules cohesion (water molecules stick to each other) and the adhesion when the water molecules stick to the channels they are running in. this is what enables water to go from the roots to the top of a tall tree.

Phagocytosis is gay right