(1)Robots could carry lift heavy things.

(2)Robots could make and serve coffee.

(3)Robots could answer the door.

(4)Robots can guard the house.

(5)Robots can understand what we say.

(6)Robots can do the gardening.

(7)Robots can greet people in English.

(8)Robots will be able to take care of the house.

(9)Robots will be able to play football.

(10)Robots will be able to design other robots.

IV

Past

(1) In the past , Robots could lift heavy things

(2)In the past , Robots could make and serve coffee

(3)In the past , Robots could answer the door

Now

(4)Robots can guard the house

(5) Robots can understand what we say 

(6)Robots can do the gardening

(7)Robots can greet people in English

Future

(8) In the future , robots wil be able to take care of the house

(9) In the future , robots wil be able to play football

(10) In the future , robots wil be able to design other robots