题目

阅读理解 Timetable Time Monday Tuesday Wednesday Thursday Friday 8:10 a.m. English English math Spanish biology 9:00 a.m. math math Self-study math Self-study 9:50a.m. biology biology Spanish art math 10:40 a.m. Self-study(自习) art P.E. biology English 12:20 p.m. lunchtime 1:10 p.m. P.E. Self-study English Self- study P.E. 2:00 p.m. Spanish(西班牙语) Span11．关于热机，下列说法是正确的（　　）A．汽油机顶部有喷油嘴，柴油机顶部有火花塞B．柴油机在吸气冲程中，将空气吸入气缸C．汽油机在做功冲程中，进气门关闭排气门打开D．汽油机在做功冲程中，是把内能转化为机械能