在LXJ局部电路中的DJ第一组前接点的作用是什么?
参考答案:
DJ第一组前接点的作用是:在信号开放前,可用它反映红灯灯泡完好,在信号开放后,可用它反映允许灯光的灯泡完好。
--What are you going to do this weekend?
--I will go to visit my grandparents _____ I have time.
A. as far as B. as much as C. as long as D as many as
患者,12岁,全口牙齿均呈均匀灰色,个别牙齿表面釉质缺损。
如何预防()
A.梅毒患者在妊娠后4个月内行抗梅毒治疗
B.居住地饮用水含氟量限制在0.5~1.0ppm
C.妊娠期、哺乳期妇女和8岁以下儿童不宜用四环素类抗生素
D.给在牙发育矿化期儿童补足营养
E.使用免疫调节剂,提高免疫力