2000A型无绝缘轨道电路衰耗盘的作用之一是用作对主轨道电路的接收端（）。
参考答案：电平调整
We all went out _____the lost boy. We had _____ everywhere, but didn't find him. [ ]
A. searching; searched
B. searching; searched for
C. in search of; searched
D. in search of; searched for
下列可发挥局部或全身作用的片剂是
A．咀嚼片
B．舌下片
C．口含片
D．颊额片
E．分散片
