That remarkable goose would lay ______ every day.

A．plants can't grow there
B．there is not enough rain
C．people haven't done what scientists wish them to do
D．scientists know little about the deserts

A．Scientists know how to change desert into good land.
B．Land is becoming desert faster than scientists can change it back into good land.
C．If scientists can bring water to desert, people can live and grow food theory.
D．More and more places are becoming deserts all the time.