1 . If you __________ able to come, I will show you around my school.

A．can be

B．will be

C．will can

D．are

2 . The advantage is that ______ there is a new illness some of these animals may die, ______ others will survive and pass on the ability to resist that disease to the next generation.

A．while; and

B．if; but

C．whether; or

D．when; for