火花塞的热特性用热值1-9数字来表示，说明热值随数字增大呈冷型趋向热型
参考答案：错
标准斜齿圆柱齿轮的正确啮合条件是：两啮合齿轮的端ˇ面模数和压力角相等，螺旋角相等，螺方向相反。
On returning home, she found a note _______ to the door, _______ “Call in later.”
A．attaching; reading
B．attaches; saying
C．attached; which reads
D．attached; reading
