新教材“人教版”教科书“必修一”第18页:
It is not unusual for teenagers of your generation to be attracted to computer games and the online world. But spending too much time online is unhealthy and makes it very difficult to focus on other things in life.
我的困惑在于But不是转折连词嘛,不是“句子A,but 句子B”嘛?为何这里But放在句首且大写了呢?