_____ wealthy people with the business tax instead of the individual income tax weakens government efforts _____ the wealth gap.
The environment will be further polluted unless some measures _____.
—May I go out tonight? —Of course you can, _____ you promise to be back before 10 o’clock.
The company ran into trouble when it tried to expand too quickly, _____ was that it was short of money.
The scenery of Jiuzhaigou Valley _____ the tourists from all over the world.
The rule demands that everyone ______ quiet in the school library.