选A.

　　倍数表达法：

　　A+谓语+倍数+the+n.(size/height/length……)+ofB

　　A+谓语+倍数+as+abj.+asB

　　A+谓语+倍数+adj.比较级+thanBA+谓语+adj.比较级+thanB+by+倍数

　　1).Thissquareistwicethesizeofthatone.

　　Thissquareistwiceaslargeasthatone.

　　Thissquareisoncelargerthanthatone.

　　2).Thisfactoryproducedthreetimesasmanycarsastheydid10yearsago.

　　3).Heis3yearsolderthanI-HeisolderthanIby3years