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.
2 He would have to refuse the invitation if he was so busy.
3 This question is long overdue to address.
4 You ought to devote more time to this work. She is very important.
5 Mail is closed now he should go to the parcel on the way home.
6 You would have to to terminate the dispute as soon realized that you are are wrong.
7 He had to argue long in order to convince everyone that he is right.
10 You would have to buy a gift for mothers on the occasion her birthday.