Knew / dialed / took / said / was / asked / was / told / didn't get / don't think / listened / told / wanted / was / has / told / was / has / wanted / can be made / told / can't be arranged / am / heard / said / wanted / didn't tell / had / could answer / rang / was / decided / was / wanted / told / happened / dialed / happened / was astonished / tried / made / didn't listen / wanted / got / said / can't understand / was bothering / tried / talked / <span>couldn't interrupt / was / hang up / wanted / was / may / didn't use</span>
<span>As a child I often dreamt of travelling in time to see how people lived centuries ago and how they will live in the future. There are many films and cartoons about time machines and I wouldn’t mind having one myself. Generally speaking, it’s a mysterious and non-existent device for travelling in time. You can read about it in science fiction books. Although it’s almost impossible to build this device, there were several secret experiments held in Philadelphia and New York during the 20th century. Various science fiction writers have tried to describe this machine. One of the first writers who described the time machine was Herbert Wells. Some parts of his imaginary machine were made from nickel, others were ivory, while the details were carved from rock crystal. There was a special saddle for the Time Traveler to sit in. The machine operated on the motion along the time axis. The only difference between the time and other dimensions is the fact that our consciousness moves over it. Other authors described the time machine as a portable device which could fit in a suitcase. It could be self-adjusting and travelling through the tunnel of the infinite past. In a fantastic story, written by brothers Strugatsky the time machine takes the form of a bicycle. </span>
Define the tense form - Present Perfect Tense - Have you ever played tennis?
Have we got many potatoes in the bag?