阅读下面短文，掌握大意，然后从A、B、C、D四个选项中选出最佳选项。    I was feeling a little blue because my mother had lost her job.
    One day, while I was 1 on the street, I heard piano music and singing rising above the noise of the people. I walked more slowly to 2 where it was coming from. Then I saw a young lady sitting at a piano.
    She was singing songs about love, 3 yourself and keeping on trying. The way she was singing made me a little comfortable. I stood there 4, watching her playing on such a crowded New York square. I thought that she must be 5 enough to perform(表演) in front of so many people.
    She noticed me. I walked over and told her how good her 6sounded. "Thank you." she said.
    "I am going through a hard time, 7 you made me hopeful again." I said to her.
    "I'm glad that I could help," she answered. "Why are you so 8?"
    "Well, my mum lost her job, and I'm not so sure what to do……"
    "Did you notice the 9 you were walking? Your head was down." she said. "Don't be worry, because10comes in different ways and if your head is down, you might not see it. You should11 more …… lift(抬) your head up. "
    I looked 12 her, surprised at how she was encouraging(鼓励) me. "13 are you playing the piano here?" I asked her with a smile.
    She 14 that she saw a lot of unhappy people in the world and she tried to make 15 happy by playing music.
    I smiled a little wider, realizing that no difficulties could stop me from going on.

将分别标有“6V 6W”的灯泡L₁和“6V 3W”L₂并联接在6V的电源上，则实际功率较大的灯是____（选填“L₁”和“L₂”），电路中干路的电流是____ A．

2015年5月4日新疆阿克陶县的牧民土尔达力•艾克热木放牧归来后，发现自己的家不见了，取而代之的是一座小冰山，附近的草场也全部被山石掩埋．原来这里发生了冰川移动，造成当地1.5万亩草场消失，70户牧民房屋受损．冰川移动发生后，原先的小盆地被冰川填埋，形成了巨大的冰山，当地的地貌也发生了巨大的变化．造成冰川移动的主要原因是全球气候变暖。造成阿克陶县地貌发生变化的直接原因是（  ）

等比数列中，则

研究能源问题，实现可持续发展已成为21世纪世界各国共同的任务。在“天然气、石油、煤炭、风能、核能”这些能源中，属于可再生能源的有____；国家发改委近日正式向国务院申报了启动核电新项目审批，现在人们用的“核电”源自于原子核____（选填“裂变”或“聚变”）释放的核能。