Black clouds had completely ___ the sun.

If you have any difficulty with this paper, you can _______ your notebooks.

Although the necklace is made of glass, it really _________ me.

Most people find it hard to ________Beijing Opera to foreigners because of cultural differences.

At the age of fifteen she gave up taking piano lessons to _____ her school work.

A cell phone could ___________the energy which could activate your brain.

She has good eyesight. She can see ____ the distant island in the sea.

Washington, a state in the United States, was named _____ one of the greatest American presidents.