用能单位应当建立( )和能源利用状况分析制度，对各类能源的消费实行分类计量和统计，

设曲线y=xⁿ⁺¹（n∈N^*）在点（1，1）处的切线与x轴的交点的横坐标为x_n，令a_n=lgx_n，则a₁+a₂+…+a₉₉的值为______．

关于惯性的理解和现象解释，以下说法正确的是（　　）

A．高速飞行的子弹具有惯性，穿入木头静止后惯性消失

B．汽车驾驶员和前排乘客系安全带，是为了减小汽车行驶中人的惯性

C．行驶中的公交车紧急刹车时，乘客会向前倾，是由于惯性力的作用

D．百米赛跑运动员到达终点不能马上停下来，是由于运动员具有惯性

肾小球内流动的液体是(   )。

A．静脉血

B．原尿

C．尿液

D．动脉血

下图表示人体与外部环境之间的物质交换模式图，数字l一7表示人体的某些结构，字母A-G代表人体内的某些物质。请据图回答：

(1)A进入血液循环的过程叫_______。

(2)进入[7]的F透过______________进入血液；组织细胞利用血液循环获得的A和F进行___________作用，释放出能量，用于维持人体的各项生理活动。

(3)健康人体内的C液与D液相比，D液中不含有的物质是_________。某人排出的D液经医院化验发现了许多大分子的蛋白质，说明图中[    ]__________部位发生了病变。

Solving a problem can be broken down into several steps. First, the problem must be identified correctly. Psychologists refer (1) this step as problem representation. For many problems, figuring (2) which information is relevant and (3) is extraneous can be difficult and can interfere (4) arriving at a good solution. Clearly, before a problem can be solved, it must be obvious (5) the problem is, however, this is not as easy (6) it might seem. One obstacle to efficient problem representation is functional fixedness, that is, allowing preconceived notions and even prejudices (7) color the facts. Most people tend (8) see objects and events in certain fixed ways, and by being inflexible in viewing the problem, they may be unable to notice the tools (9) the solution. Once the problem is identified accurately, (10) , the second step consists (11) considering the alternatives for a solution. A common way to evaluate alternatives is to write them (12) and then make a list (13) advantages and disadvantages for each solution. Here again, people may be limited by prior experiences. Often people adopt mental sets (14) lead them to the same problem-solving strategies that were successful for problems (15) the past. Although that can be helpful most (16) the time, sometimes a new situation requires a different strategy. (17) that case, the mental set must be abandoned, (18) new alternatives must be explored.
After the alternatives have been compared, a strategy must be selected (19) among them. One way to avoid becoming mired in the options is (20) try the best option with a view to abandoning it for another (21) the results are unfavorable. This attitude allows many people to move on expeditiously (22) the next step—action. The strategy selected must be implemented and tested. If it solves the problem, no further action is necessary, but if (23) , then the cycle begins again, starting (24) problem identification. By continuing to review the problem (25) repeat the problem-solving steps, the solution can be improved upon and refined.