He _______ busy yesterday, or he _______ you with your experiment.

A．was; had helped

B．was; would have helped

C．had been; would have helped

D．were; would have helped

某学校拟建一座5层砖混结构办公楼，首层平面图如图2所示。二层及以上各层除将首层M2的位置改为C2外，其他均与首层平面相同，层高均为3.00m，层顶盖标高15.0，女儿墙顶标高 15.60m，室外地坪为-0.5m，门窗框外围尺寸及材料见下表。求：

1．办公楼建筑面积。

2．水泥砂将外墙抹灰工程量。

3．门窗工程量。

门窗框尺寸表　 单位：mm²