The last time Dominique traveled on an airplane she took an antihistamine before her flight to keep her ears unclogged and prevent an earache. Dominique took an antihistamine to prevent a(n) response to the airplane's environment.

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands