什么是绝对相力与相对压力？
参考答案：
绝对压力是以绝对真空为基准/相对压力是以大气压力为基准，也就是一般压力表所测得的压力值。
-The boss said we had only three days to finish the work.
-Don't worry. We have already _____two thirds of it. [ ]
A. got down
B. got through
C. given in
D. given away
乳牙期矫治的非适应证（）
A．严重拥挤
B．严重深覆
C．前牙反
D．不良习惯
E．以上都不是
