The price of oil has _________ sharply to $12 a barrel.

John is liked by his sons, partly because he’s to understand children.

The bamboo forests are becoming smaller. As a result, pandas not have a place to live or food to eat.

Had he _____her promise, she would have made it to Yale University.

Only a small number of students able to pass the exam.—Yes．The number of the students no more than 20.