人体的不同部分如皮肤、血液、肌肉及关节等对电流呈现的阻抗称为（）
A、接触电阻
B、表皮电阻
C、绝缘电阻
D、人体电阻
参考答案：D
根据答语写出问句。
1. —__________________________?
—My books are on the desk.
2. —__________________________?
—His baseball is under the chair.
3. —__________________________?
—Yes, it is. My hat is on the bed.
4. —__________________________?
—No, they aren't. Her pencils are not in
the bookcase. They are in her desk.
5. —__________________________?
—Their plants are on the table.
LAND3、LAND2这两种显示在何时出现？（）
A、飞机在地面时
B、飞机在巡航时
C、在1500英尺以下多通道进近时
D、在1500英尺以下单通道进近时
