关于PD140金属探测器灵敏度调节及操作指导的描述，下列正确的是（） A.PD140
题型：多项选择题
问题：
关于PD140金属探测器灵敏度调节及操作指导的描述，下列正确的是（）
A.PD140金属探测器配备有灵敏度调节钮，有三挡可选择
B.若使用PD140高灵敏度型号，调节钮为连续调节型，以确保精细校准
C.一般情况下，灵敏度应设在高档
D.PD140金属探测器的敏感探测区域位于装置的下部平面区内，测量面积为60x140mm
题型：多项选择题
冠词填空。不
需要的可以划X。
1. There is _____ picture of _____ elephan
t on _____ wall.
2. This is _____ useful book. I
've read it for _____ hour.
3. _____ elephant is much heavier than _____ horse.
4. _____ doctor told him to take _____ medicine three times _____ day.
5. Let's go out for _____ walk.
6. It's too hot. Open _____ door, please.
7. There is _____ woman over there. _____ woman is Meimei's mother.
8. _____ sun rises in _____ east.
9. _____ 
Changjiang River is _____ longest river in _____ China.
10. Are you going to do it _____ second time?