题目

 — Jim, how did your English test go?    — I had thought I ________, but luckily I came top in the list in class.    A. should have failed                        B. could have failed    C. need have failed                          D. might have failed 答案：D 原癌基因发展成癌基因并使人患癌症的过程大致如下： (1) A处的转变因素有________。 (2) 人在正常情况下不患癌症是因为________。 (3) 在日常生活中应如何防护、远离癌症？