单项选择题 It was the first time she ______ at a summer school and she enjoyed it greatly. A．was B．has been C．had been D．is

单项选择题 脑干损伤瞳孔变化的特征为( ) A．双侧瞳孔散大、固定 B．伤后双侧瞳孔立即缩小 C．一侧瞳孔进行性散大，对光反应消失 D．双侧瞳孔大小多变，不等圆 E．两侧瞳孔等大，对光反射灵敏

单项选择题 The boy ______ .A bullet ______ through his chest on the left side. A．had died; passed B．died; had passed C．died; passed D．had died; had passed