[填空题]At a refinery the crude oil is ______ into its various parts.

[单项选择]

In a refinery, the capacity of oil tank A is 70 per cent of the capacity of oil tank B.
How many more gallons of oil are in tank A than in tank B （）
(1)Tank A is 90 percent full; tank B is 50 percent full.
(2)When full, tank A contains 50,000 gallons of oil.

A. 条件（1）充分，但条件（2）不充分.
B. 条件（2）充分，但条件（1）不充分.
C. 条件（1）和（2）单独都不充分，但条件（1）和条件（2）联合起来充分.
D. 条件（1）充分，条件（2）也充分.
E. 条件（1）和条件（2）单独都不充分，条件（1）和条件（2）联合起来也不充分.

[单项选择]Many years ago there was a huge oil refinery fire. Flames shot hundreds of feet into the air. The sky was thick with black smoke. The heat was so intense that firefighters had to park their trucks a block away and wait for the heat to die down before they could begin to fight the fire. However, it was about to rage out of control.
Then, all of a sudden, from several blocks away came a fire truck racing down the street. With its brakes screeching, it hit the curb in front of the fire. The firefghters jumped out and began to battle the blaze. All the firefighters who were parked a block away saw this, and they jumped into their trucks, drove down the block and began to fight the fire, too. As a result of that cooperative effort, they were just barely able to bring the fire under control.
The people who saw this teamwork thought: "My goodness, the man who drove that lead fire truck—what an act of bravery!" They decided to give him a special award to recognize him for his bravery
A. They stayed where they were and continued fighting the fire.
B. They drove down the block and fought the fire fearlessly.
C. They went back to the safe area.
D. They came to help save the wounded.