这是什么交通标志？
A、两侧变窄B、右侧变窄C、左侧变窄D、桥面变窄
参考答案：C
解析：
两侧变窄
右侧变窄
左侧变窄
_______ advantages and disadvantages, Mr. Smith decided to leave the company and go to the west to try his fortune.
A．Having compared
B．Having balanced
C．Having observed
D．Having examined
克雷伯杆菌感染（）
A.粉红色泡沫样痰
B.脓血痰
C.砖红色胶冻样痰
D.铁锈色痰
E.脓臭痰
