Answer:
They lose their end walls so the xylem forms a continuous, hollow tube. They become strengthened by a substance called lignin . Lignin gives strength and support to the plant.
Answer:
It has gotten worse.
Explanation:
In the past 30 years, air quality in the United States has declined almost exponentially. Pollution is the main reason for the declination of air quality in the United States, but there are different kinds of pollution, including light pollution, noise pollution, air pollution, water pollution, etc. Air pollution can be caused by primary or secondary pollutants. Primary pollutants include carbon, nitrogen, and sulfur oxides as well as just general particles in the air. Secondary pollutants are formed when pollutants are exposed to sunlight via chemical reactions.
The mesencephalon gives rise to the midbrain and aqueduct of
the midbrian(cerebal aqueduct). Both the prosencephalon and rhombencephalon
develops in to the metencephalon and myelencephalon. The telencephalon develops into the cerebrum
and lateral ventricles. The diencephalon forms the thalamus, hypothalamus, and
epithalamus.
B. Ocetoclast is the answer.
