a) The experimental battery car has made at most 60 km without recharging of the batteries.
Глагол сказуемое has made - past perfect, 3-е лицо (it), ед. ч.
Экспериментальная аккумуляторная машина не более 60 км без подзарядки аккумуляторов.
b) People knew that the electric current was the motion of electrons through an electric conductor.
Глагол сказуемое knew - past simple, 3-е лицо (they), мн. ч.
was - past simple, 3-е лицо (it), ед. ч.
Люди знали, что электрический ток-это движение электронов по электрическому проводнику.
c) Now the workers are laying down the track.
Глагол сказуемое are laying down - present continuous, 3-е лицо (they), мн. ч.
Сейчас рабочие прокладывают путь.
I went into the kitchen and saw that the rubbish bin needed emptying. So I picked up the bin liner and went to take it outside. I opened the front door and went along the corridor to the place where you leave your rubbish. As I was putting the bag down I felt a draught of air and heard a bang. When I came back to my flat, I saw that the door was closed. The wind had blown it shut. I put my hand in the pocket of my pyjamas, but I had left my keys inside. So I went down to the security man to phone my husband. But they told me he had gone to China for the day! I tried ringing my neighbour's door bell, but they had already gone to work. So I had to wait all day in the corridor outside my flat!