The two astronauts______ someday hope it is to fly the craft into earth orbit were fight testing.

单项选择题Children going to school must have a chance to______ excess physical energy; children even more than adults require and enjoy physical exercise and games of all kinds.

单项选择题Children between the age of 2 and 11 cannot comprehend the difference between commercials and television, so they cannot defend themselves against the______ techniques of commercial television advertising.