问题
单项选择题
Recent studies have identified four major global environmental risks; acid rain, ozone depletion, deforestation and the greenhouse effect.
A．recognized
B．proved
C．got rid of
D．multiplied
答案
参考答案：A
解析：recognize认可，承认；prove证明，检验；get rid of消除；multiply繁殖，增加；identify识别，鉴别。