题目

The life we were used to _______ greatly since 1992. A．change                                                      B．has changed C．changing                                                    D．have changed 答案：B校园里的单双杠、篮球架、广场内的健身器材等铁制品由于表面的油漆或涂层脱落易产生铁锈，请你根据所学知识，指出铁生锈的条件是什么？