In the 21st century, all nations must take their __________ of responsibility for the global safety.
| A．blame | B．charge |
| C．share | D．notice |
—Flight MU257 ____ . I must be off now.
—Have a nice trip.
| A．is being announced | B．has announced | C．was announcing | D．had been announced |
When ____ comes to saving energy, big changes start with small steps, like turning off the lights.
| A．that | B．this | C．it | D．one |
Of the two cameras, I would prefer_____ one, which is very easy for me to carry.
| A．a smaller | B．the smallest | C．a small | D．the smaller |
Mr Jones, a professor, ____ for his excellent lectures, is popular with his students.
| A．known | B．knowing | C．to be known | D．having known |
—Can you give some advice on what I said just now?
—Sorry. My mind____.
| A．is wandering | B．was wandering | C．has wandered | D．had wandered |