计算题： 取水样500ml，经萃取后定容至50.0ml，取25.0ml测定萃取液中总萃取物的浓度为45.2mg/L，另25.0ml经硅酸镁吸附后测得萃取液中石油类的浓度为33.8mg/L，分别计算该水样中石油类和动植物油的浓度。

A. 5、6
B. 17、18
C. 19、20
D. 21、22

A. Temperature falls below normal，pulse is rapid and feeble，skin is cold and clammy
B. Temperature is high，pulse is strong and rapid，skin is hot and dry
C. Temperature is high，pulse is slow and feeble，skin is clammy
D. Temperature falls below normal，pulse is rapid，skin is clammy