1 . It is worth ________ to stay in touch with your friends, for you can turn to ________ for help when in trouble.

A．that; themselves

B．it; themselves

C．those; them

D．it; them

2 . Elephants are among the longest living animals, and some of ________can live up to 70 years in the wild.

A．which

B．whom

C．them

D．that