1.It is reported that a new type of car which can___30% of the petrol____and it will be received.
A.save;has been produced B.save;have been produced C.saves;has been produced D.save;have produced
2.When the old man___to walk back to his house ,the sun ___itself behind the moutain.
A.started;had already hidden B.had started;had already hidden C.had started;was hiding D.started;hid
3.It's the fourth time you ___late for school this month.
A.were B.are C.had been D.have been
4.The watch ____there unnoticed for several days before I found it.
A.had laid B.had lain C.has been laying D.had been laid
5.I thought that these computers cost $850.but the price_____up $50.Do you know that?
A.went B.will go C.goes D.has gone
请写清楚详细过程,越详细越好,谢谢