There were so many people watching the fire that firefighters couldn't get close____the building

我国某出口企业向美国出口机器设备，当美元与人民币的兑换比率为1∶6时，每出口一套价格为12万美元的设备，可获利36万元人民币。当人民币对美元贬值20%，在成本不变的情况下，此时该企业每出口一套设备，获利（  ）

已知等差数列{a_n}的前n项和为 $S_n$ ，若 $\overrightarrow{OC}=a_1\overrightarrow{OA}+a_{2015}\overrightarrow{OB}$ ，且满足条件 $\overrightarrow{AC}=2\overrightarrow{CB},则S_{2015}$ =（    ）

2015•北京）小阳在探究“电路中一个可变电阻两端电压U与通过它的电流I的关系”时，得到如下表所示的实验数据．请根据表中数据归纳出U与I的关系：U=　____ 　．

I/A	0.2	0.4	0.6	0.8	1.0	1.2
U/V	7	6	5	4	3	2

阅读下面短文，从各题所给的A、B、C、D四个选项中选出最佳选项。
B
Join Us for a Day at Sun Valley Amus ement Park

    Children aged 10 to 14 are invited to take part in the "Event of the Summer" at
Sun Valley Amusement Park, the most popular amusement park on the East Coast.
Sun Valley has more than 80 amusement rides. For sports lovers, there are
basketball courts, an indoor baseball field and climbing walls.
    No amusement park would be complete without a gift shop. Sun Valley
has two.
    You won't want to miss out on this day of fun. Join us at Sun Valley Amusement Park on July 14. Register (登记) early.
    • The cost of the trip is $ 25. This includes tickets and all rides.
    • We suggest that all children bring lunch.
    • Buses leave at 9.00 AM and return at 5.00 PM.
    • Rain Date: Wednesday, July 16.
    Register at the Children's Recreation Center at the Town Hall by July 3.
    A one-day registration will also be held on July 1 at the Brown School.
    For more information, call Jane Parks at 555-7267.