题目

The Internet and the World Web (网) are great places to be right now. We use the word place because so many of the things you can do online are similar to the things you can do wherever people gather together－in homes , schools , libraries , shopping centers , or at family reunions(团聚)or town meetings. The Net allows people to learn shop, find important information, and communicate, whether they're local, global or simply virtual (虚的) . The Web is useful. You can find old friends online. You can research and book flights, check the weather, find breaking news, find out infor大规模的火山爆发可能造成地表温度下降。其合理的解释是火山爆发导致（ ）A. 大气二氧化碳浓度增加 B. 到达地面的太阳辐射减弱C. 地球表面长波辐射增强 D. 高纬度地区极光现象减少