Conteste la siguiente pregunta usando el pronombre correcto. ¿Comprenden ustedes esta teoría?
A. Sí, lo comprenden.
B. Sí, las comprenden.
C. Sí, la comprendemos.
D. Sí, los comprendemos.

Ithink los discos compactos.

The correct answer is
1. black death

a deadly plague that swept through europe between 1347 and 1351, it killed one third of european population, but the left food supply give chances to survivors for advancement.

and

2. smallpox

an eradicated virus that used to be contagious, disfiguring, and often deadly.