The ________ system is relatively slow acting, and involves molecules secreted into the bloodstream, while the _____________ system is fast acting, and involves impulses sent directly to specific cells.
a. Endocrine; Nervous
b. Nervous; Lymph
c. Circulatory; Integumentary
d. Lymph; Endocrine
e. Lymph; Nervous
f. Circulatory; Lymph
Answer: a. Endocrine; Nervous