The six-banded armadillos eat vegetable because ______.

A．Because nationals are extremely strict in choosing journalists.
B．Because nationals have already employed many journalists.
C．Because nationals pay little salary.
D．Because nationals seldom recruit inexperienced employee.

A．He worked for a medical periodical.
B．He published a paper about computer science.
C．He suggested a link between smoke and lung cancer.
D．He opened a hospital with his partner.