Many years of hard work_______ his great success in the development of this new type of material.
| A．due to | B．thanks to | C．contributed to | D．looked into |
All passengers ______ are expected to fasten the seat belts when the plane takes off and lands．
| A．on aboard | B．on board | C．on the board | D．on boards |
Yellow Stone National Park, ________in 1872, _________over three million visitors every year, is America’s first and foremost National Park．
| A．establishing, attracted | B．having established, attracted |
| C．established, attracting | D．being established, attracting |
Without this year’s Nobel Prize in physics winner Charles Kao’s idea of fibrotic（光纤的）communications, the “modern” telephone and Internet _________impossible．
| A．will be | B．were to be | C．should be | D．would be |
–Do you need any help, Lucy?
-Yes. The job is ________ I could do myself.
| A．less than | B．more than | C．no more than | D．not more than |
It was yesterday _______I saw her and it was almost 10 o’clock ____she arrived.
| A．when, when | B．that, that | C．when, that | D．that, when |