Scientists from different countries are trying to_____ a good way to solve the energy problem.

The peopleall over the world were deeply____by the news that SteveJobs, the founder and former CEO of Apple, died on Oct.5.[ ]

Can you ______ the fact that we are already senior high school students?

inch ________, compared with the 4-inch screen of the current Iphone 5s, is being prepared for mass production and may be available around this September.

You can’t take the lift because it is _______