氧传感器可分为（）和（）两类。
参考答案：氧化锆、氧化钛
请将如图所示的电路补画完整：在图中①和②的缺口处分别画出开关或灯泡的电路符号，并把③处的三孔插座连入电路．
He just _______ the headlines because he was too busy to read the whole newspaper.
A．stared at
B．looked around
C．glared at
D．glanced through
