I _______ this computer five years ago.
A:buy
B:bought
C:have bought
D:has bought
例句:入团那天,春光融融,蓝蓝的天上飘着白云,校园里绽放着鲜花,团旗映着我们的面颊。那一刻,我的心里,蓝天如同浩瀚的海洋;白云____;鲜花犹如我们灿烂的未来;团旗____。