一般蒸气雾化火嘴所需的油压和蒸气压力不低于（）MPa。
A、0.2
B、0.3
C、0.4
D、0.5
参考答案：C
17.5乘一个小数，积一定小于17.5______．
David must be excited about something and you can ______ it from the look on his face
A．read
B．fetch
C．direct
D．approve
