-I want to see Mr. White. We have an appointment.
-I'm sorry, but he is not ________ at the moment, for the meeting hasn't ended.
busy
active
concerned
available
________of the people on the Net ________China's economy is among the strongest in the world.
Nobody but doctors or nurses and those ________ by Dr. Hu ________ to enter the patient's room.
The population of China ________ 1.3 billion,and 80% of the population________farmers.
Every possible means ________ to prevent the air pollution,but the sky is still not very clear.
It is reported that 40 percent of the land in Brazil________covered with trees.