阅读理解

    I am a karate(空手道) player. I still remember my first karate competition. Like other players,

I was very excited about my event. I watched every player's skills so that I could carefully avoid their moves.

    Somehow, I got into the semifinals(半决赛). In the semifinals, I fell down and hurt myself. I still didn't give up, so I fought back and got into finals. After all, getting the gold medal was my dream.

    In the final competition, there were no supporters on my side, as I was a new face. Instead, the crowd was cheering for my opponent(对手). I could hear only my opponent's name.

    I didn't mind the crowd's cheering. I kept one thing in mind: focus, wait and attack. I had confidence in myself, and I knew that no matter how strong my opponent was, I had to give it my best shot and fight well.

    When the time was up, I was leading with a 3—0 score. One thing I learned from that event is, no matter how strong your opponent is, don't think you are weak or strong. Just give your best shot, and you will make your way to success.

    Win or lose, you will gain important experiences. Learn from every step you take.

如图甲所示的电路中，理想变压器原、副线圈匝数比为10：1，电流表、电压表均为理想电表，R是光敏电阻（其阻值随光强增大而减小）．原线圈接入如图乙示的正弦交流电压u，下列说法正确的是（   ）

    午后一点左右，从远处传来隆隆的响声，好像闷雷滚动。顿时人声鼎沸，有人告诉我们，潮来了！我们踮着脚往东望去，江面还是风平浪静，看不出有什么变化。过了一会儿，响声越来越大，只见东边水天相接的地方出现了一条白线，人们又沸腾起来。 那条白线很快地向我们移来，逐渐拉长，变粗，横贯江面。再近些，只见白浪翻滚，形成一堵两丈多高的水墙。浪潮越来越近，犹如千万匹白色战马齐头并进，浩浩荡荡地飞奔而来；那声音如同山崩地裂，好像大地都被震得颤动起来。

科学兴趣小组模拟上述流程，在实验室中制备氢氧化钠。