Hi, 小马GE: A. on whether significant warming will occur and what impact will it have if it does. B. on whether warming that occurs will be significant and the impact it would have C. as to whether significant warming will occur or the impact it would have if it did D. over whether there will be significant warming or the impact it will have E. over whether significant warming will occur and what impact it would have A: "will it" should be "it will" B, C & D: the green words should be a clause. Also, "as to", "or" are wrong. E is correct |