BY THE YEAR 2100 . . .

Use the Future Perfect.

(will have + 3rd form)

Humans ………….. (travel) to Mars.

We …………… (use) up all the fossil fuels.

Robots …………. (be invented) to do all the work.

The world’s population ………… (double).

Doctors ………….. (discover) a cure for cancer.

Scientists …………… (find) new resources of energy.

Flying cars …………… (be used) by everybody.

Temperatures ………… (rise) by several degrees.

Intelligent houses ………….. (be built) for all people.

Oceans ……………. (be populated) by humans.