2010年新年伊始，一场罕见的暴雪降落北方大地，某校七年级学生小明没等父母要求，就主动清扫积雪。这一行为体现了[ ]

A、小明正在经历一个转变，其行为由外在因素支配变成心中自觉的要求

B、小明已经完全走向成熟

C、小明喜欢下雪

D、小明想在雪天锻炼身体

Without the invention of the computer, much of today's advanced technology _______.[ ]

A. will not have been achieved    

B. would not have been achieved

C. have not been achieved        

D. had not been achieved