有三元催化剂的电喷发动机对油气比例要求不高，一样可获得好的动力性能和经济性以及排放性。
参考答案：错
As students, we are supposed to _______ more time _______. [ ]
A. spend, studying
B. take, to study
C. spend, play computer games
D. take, to watch TV
上腔静脉造影常做哪根血管穿刺插管
A．股动脉 B．股静脉C．肘动脉 D．贵要静脉E．肱动脉
