When the body is attacked by a foreign substance, the defenses are the first to react.
A. nonspecific
B. B lymphocyte
C. specific
D. T lymphocyte

What best explains the inability for life to exist in earth early atmosphere

Why do we perceive objects as retaining their brightness under different lighting levels?

Which best describes the scientific method? a. a path of clearly defined steps that must be followed in a particular order b. a possible answer to a scientific question based on knowledge or research c. the recipe for how to conduct an experiment that must be followed precisely d. the process of hypothesis and testing through which scientific inquiry occurs