根据世界卫生组织(wH0)规定的噪音标准,白天病区较理想的噪音强度是()
A.5~15dB
B.15~25dB
C.25~35dB
D.35~45dB
E.45~55dB
参考答案:B
Upon ______ the office, he saw the message on his desk.
A.he arrived
B.arrived at
C.arriving at
D.arriving
The teacher, ____ his book ____ hand, came over to the
blackboard.
A.with; in
B./; in
C.on; on
D.with; /