阅读理解
    Recently, an Internet game has become a new fashion among young office workers and students. People can “farm” on a piece of “land” and “grow”, “sell” or even “steal” “vegetables”, “flowers” and “fruits” on the Net. They can earn(挣) some e-money and buy more “seed”(种子), “pets” and even “houses”.
    Li You from Xi'an said people in the city get tired from work, they go to their own farms, take care of their crops(庄稼), and pull out weeds(杂草). It is glad to forget about the pressure in cities.
    Li Bu grew up in a small village, and then he went to a city, but now he misses the life in the village and “Happy Farms” makes the country dream possible in his office. He said every time he sees his crops, dogs, and grasses, he feels like he is in the village again. When he is working on his farm, he can feel the breath of nature, and get happiness from farming and harvesting(收获).
    Li Lei enjoys putting some “bugs”(虫) in my friends' garden and they've become closer because of the game. Having fun together is the most exciting thing about it.
    Li Hong said it was just a waste of time. Teenagers spend so many hours on it and they can't focus on their study.

如图所示，一理想变压器原、副线圈的匝数比为n:1. 原线圈接正弦交变电压U，副线圈接有一个交流电流表和一个电动机. 电动机线圈电阻为R，当变压器的输入端接通电源后，电流表的示数为I，电动机带动一质量为m的重物以速度v匀速上升，则下列判断正确的是〔 〕

大多树叶在秋季由绿色变成橙黄色，其原因主要是（   ）

下图表示果蝇X染色体上的部分基因位点。下列有关叙述中，错误的是(    )

下图为某国简图，其经济以农牧业为主。读图．完成下列各题。