Choices:
(1). flies;
(2). Allergies;
(3). tadpoles;
(4). heat produced;
(5). an object;
(6). Chlorophyll;
(7). chemicals;
(8). water;

Fact 1: Amphibians have sense organs to smell and taste chemicals. Fact 2: Amphibians also have immune cells arranged into organs. Given the two facts above, amphibians also have immune cells arranged to smell and taste what?
Answer:
(7).