They ___ have arrived at lunchtime but their flight was delayed.
| A．will |
| B．can |
| C．must |
| D．should |
He had to pause from time to time to wipe the sweat from his forehead, because the air-conditioning system ____.
| A．broke in | B．broke up | C．broke out | D．broke down |
Computers and mobile phones, though they are indeed making our life ____ and more ____, have reduced the need for face-to-face communications.
| A．easily; efficient | B．easier; efficient | C．easy; efficiently | D．easily; efficiently |
The woman ____there under the tree, ____ in a blue shirt, is our headmaster.
| A．sitting; wearing | B．sitting; dressed | C．seating; dressed | D．seated; dressing |
The new technology, if____ to farming, will help increase the grain output.
| A．applying | B．to apply | C．applied | D．having applied |
More and more high-rise buildings have been built in big cities____ space.
| A．in search of | B．in place of | C．for lack of | D．for fear of |