一般过去时,特殊疑问句：特殊疑问词+did+主语+动词原形-He died in 1919. 他是1919年去世的。-When did he die? 他是什么时候去世的？,一般过去时,-Why did they want him?他们为什么要找他？ -Because they needed him to help them.因为他们需要他的帮助。 -How long did the space flight last?这次太空飞行持续了多长时间？ -It lasted twenty-one hours.持续了21个小时。,
