我国将减轻小排量乘用车税负、增加大排量乘用车税负，并停止执行对1.6升及以下排量乘用车购置税优惠政策。针对这些政策的调整和油价上涨的趋势，在商量购买家庭用车时，某同学根据经济生活知识向父母提出了以下建议，其中合理的是[ ]

①优先考虑购买小排量汽车和新能源汽车　

②在汽车销售处于卖方市场时应及时购买　

③油价不断上升时应购买汽车的互补商品　

④如果贷款买车待贷款利率下降时购车

A．①②

B．②③

C．③④

D．①④

My sister _____ as a secretary in her company for three years and now she _____ to the manager of the sales department.

A．served; has been promoted

B．had served; has been promoted

C．has served; has promoted

D．was serving; has promoted