某家有“220V 500W”洗衣机一台，“220V 25W”的灯泡四只，“220
题型：填空题
问题：
某家有“220V 500W”洗衣机一台，“220V 25W”的灯泡四只，“220V 100W”的电冰箱一台，如果这些用电器同时使用，电路中的总功率是 W，若每天平均用电4小时，则每月（按30天计）消耗的电能是 度。
题型：填空题
Many of us invest valuable time，energy and money planning our vacations. We do this because we know for sure that going on vacations must be good for us. Research proves this feeling without a doubt. Vacations help us perform better at work, improve our sleep quality and cushion us against depression.
Yet, despite these benefits, many of us return home with a feeling that our last vacation was OK - but not great. In order to change this, some mistakes should be avoided. A classic one for vacation planners is attempting to maximize value for money by planning trips that have too many components (组成部分)• Perhaps you’re planning a trip to Europe, seven cities in 10 days，and you realize it will cost only a little more to add two more destinations to the list Sounds fine in theory, but hopping from one place to the next hardly gives an opportunity to experience what psychologists call mindfulness - time to take in our new surroundings, time to be present and absorb our travel experiences. Another mistake is that we worry too much about strategic issues such as how to find a good flight deal，how to get from A to B，or which destinations to add or subtract from our journey. These issues may seem important, but our psychological state of mind is far more important.
Actually, vacation happiness is based on the following top rules. First, choose your travel companions wisely, because nothing contributes more significantly to a trip than the right companions. Second，don’t spend your vacation time in a place where everything is too expensive so as to maintain a positive mood. Third, shop wisely, for meaningful experiences provide more long-term happiness than physical possessions.
