Michael Jackson, a superstar, _______ at the age of 50 in Los Angeles.

________ those who were not listening the first time, I will repeat the question.[ ]

People often use plastics to ______ wood or metal.

______ private cars are bringing us convenience, they also cause more traffic accidents and pollution

the baby milk powder was found to be polluted,there has been universal doubt _____ other food products are safe _____.