In the next 100 years,
In the early 1990s,
In many schools today,
Before there were supermarkets,
Before the airplane,
In most big cities nowadays,
In many companies today,
Sometime in the near future,
students have their own tablets.
pollution is becoming a serious problem.
people used to shop at small grocery stores.
there will probably be cities in space.
ocean liners were the only way to travel across the Atlantic.
doctors might find a cure for the common cold.
women still receive lower salaries than men.
few people had cellphones.
