______ that the environment continues to be damaged at the current rate, it will not be long before the earth is totally destroyed.
【正确答案】
B
【答案解析】concern和regard均可作动词，但concerning和regarding可作介词，意思为“有关，关于”，后面不直接跟that从句，如：Regarding the punishment，what would you advise?ascertain“确定(事实)，探知”；assume“假定，假想”，assuming可以作连词表示“如果”，相当于given。B为正确答案。