车辆在行驶时突然熄火的原因？
参考答案：
车辆中途突然熄火，主要原因是油管破裂，高压油泵不能供油，油箱油位太低造成不供油，使车辆中途熄火。
The tourists will find the guide book is of even ________ practical value than they thought, as it shows different routes to the places they are going to.
A．less
B．little
C．great
D．greater
凝汽器为什么要装自动排汽门？自动排汽门有几种形式？
