过去一百五十多年来全球平均表面温度的变暖速度约为（）。
A、每年0.06℃
B、每十年0.06℃
C、每百年0.06℃
D、每千年0.06℃
参考答案：B
简述化学选矿的原理？
For each person it is certified to carry，a lifeboat on an oceangoing passenger vessel must be provided with all of the following EXCEPT（）.
A.3 litres of water
B.1 unit of provisions
C.1 seasickness kit
D.1 life preserver
