南极地区至今无人定居，其大气中破坏臭氧的氟氯烃来自（）
A.南极科学考察
B.大气环流输送
C.大洋环流输送
D.极地航线飞机
参考答案：B
皮肤表面的温度（）。
A.称为心理零度
B.一般是指37℃的温度
C.称为生理零度
D.是皮肤不觉得热和凉的温度
Green economy offers a new model ______ people could both protect the climate and develop the economy, according to what Li said at the International Cooperative Conference on Green Economy and Climate Change.
A．how
B．why
C．where
D．which
