房屋租赁行为应有明确的租赁期限，出租人有权在签订的合同中明确租赁期限，并在租赁期限届

右丙氧芬的化学结构为（）.

A．氟他胺 

B．非那雄胺 

C．左炔诺孕酮 

D．丙酸睾酮 

E．达那唑

汽车由静止开始在平直的公路上行驶，0～60s内汽车的加速度随时间变化的图象如图所示．则该汽车在0～60s内的速度-时间图象（即v-t图象）为下列的（　　）

A．

B．

C．

D．

砂浆回弹法测试碳化深度时应用浓度为（）的酚酞酒精溶液。

A.1%-2%

B.2%-3%

C.3%-4%

D.4%-5%

某钢厂去年产钢740万吨，消耗各种耐火材料221225吨，今年计划产钢850万吨，要求吨钢耐火材料消耗要降低2%，求今年耐火材料需用量。（提示：耐火材料消耗与钢产量成正比）

In a traditionally drawn decision tree，a circle represents （）．

A．a chance to which no estimated monetary value can be assigned so that a likely pay-off can not be shown

B．a decision to which no estimated monetary value can be assigned so that a likely pay-off can not be shown

C．a chance to which an estimated monetary value may be assigned to calculate the most likely pay-off

D．a decision to which an estimated monetary value may be assigned to calculate the most likely pay-off