Определите в каждом предложении модальный глагол или его эквивалент. Переведите на русский язык.

1. We can think of heat as a special form of kinetic energy.
2. A computer should solve complicated problems many millions of times faster than a mathematician.
3. New types of plastics had to be obtained for space technology.
4. To measure the temperature of gases, the scientists have to use special devices.