已知：①闭合S₁和S₃、断开S₂时，调节R₁，使其接入电路的阻值为20Ω，此时电路的总功率为14．4W；

②闭合S₁和S₂、断开S₃，调节R₁，当电压表的示数为15V时，电流表读数为0．22A．

如图甲为某湖泊生态系统的能量金字塔简图，期中Ⅰ、Ⅱ、Ⅲ、Ⅳ分别代表不同的营养级，m₁m₂代表不同的能量形式．图乙表示能量流经该生态系统某一营养级的变化示意图，其中a～g表示能量值的多少，请据图回答：

（1）图甲中，m₁、m₂表示的能量形式分别为____ 、____．通常情况下，位于营养级Ⅳ的生物个体数量一般远远少于Ⅲ，主要原因是____ 

（2）图乙中，若A表示图甲中营养级Ⅱ所摄入的全部能量，则B表示____ ，C表示____ ．若图中营养级Ⅰ所固定的太阳能总量为y，营养级Ⅰ、Ⅱ间的能量传递效率是____ （用图中所给的字母的表达式表示）．

（3）由图乙可以总结出生态系统能量流动的主要特点是____．

阅读理解

                                                                                             (B)

       For the British, the home is private place in which he or she goes to hide away from the troubles of life. It is very seldom that one would be invited to a British person's home. It is rude to knock on a person's door if you are not invited. If you are invited, don't ask to see more than the downstairs that your British host invites you into. Never ask how much the house or any of the items in if cost.
       To the American, most of them want their home to be a place where they can entertain (款待) and share their lives with their friends. They may be delighted to give you a full tour of their houses. They may also be pleased when you show your interest and pleasure in their houses.
       Both British and American people will engage in quite a bit of chat and a drink or two before the meal is served. After the first mouthful, you should say how delicious the food is and ask something about it. Remember, never eat with your mouth open and make very little noise while eating. It would be nice of you to help your host in any way. Maybe offer to pour some drinks or clear up after the meal.

关于x的方程$\frac{a}{x+1}=1$的解是负数，则a的取值范围是（）