—Noonecanachieveanythingofreal-优题课

—No one can achieve anything of real significance he works very hard.
— I got it, Dad. I’ll study hard from now on.

A．because

B．if

C．unless

D．when

科目英语题型单选题难度中等

___ by the advances in technology,many farmers have set up wind farms on their land.

___ many times, he finally understood it.

___ the right kind of training, these teenage soccer players may one day became the international stars.

___ not to miss the flight at 15:20, the manager set out for the airport in a hurry.

___ twice, the postman refused to deliver our letters unless we chained our dog.