He collected information on 1,000 people, whose IQ when they were ten years old.
A．is tested B．has tested C．would test D．had been tested
He collected information on 1,000 people, whose IQ when they were ten years old.
A．is tested B．has tested C．would test D．had been tested
D
考查时态。Test的动作发生在collect之前，应该用过去完成时。