发现原料油缓冲罐液位下降,应()。
A.了解原料油性质
B.检查液位控制阀开度输出信号
C.检查界区进料流量
D.检查液位控制阀实际开度
参考答案:B, C, D
Little _____ at that time that this“boring”subject would become his favourite later on.
A.he knew
B.he has known
C.did he know
D.has he known
X线胸片有偏心空洞,内壁凸凹不平()
A.肺炎球菌肺炎
B.肺癌
C.葡萄球菌肺炎
D.肺结核
E.肺脓肿