[多项选择]19世纪由于建立了电磁理论，从而创造了发电机、电动机，使人类进入了电气化时代。这一历史事实说明（）。
A. 科学理论与实践相结合，可以转化为物质力量
B. 科学理论是认识的基础，对实践起决定作用
C. 科学理论的任务不仅在于认识世界，而更重要的在于改造世界
D. 科学理论可以指导实践

{{B}}Depression and the Elderly{{/B}}
1 We all feel sad at times. However, clinical depression is a serious matter. Clinical depression, sometimes called major depression, is a biologically based brain disorder that affects one’s thoughts, feelings, behavior, and physical health. When people complain that they feel terrible, they have no interest or take no pleasure in things, have trouble sleeping, lack energy, have poor appetite, or cannot concentrate, depression is a definite possibility.
2 Depression in its many forms affects more than 6.5 million of the 35 million Americans who are 65 years or older. Most older people with depression have been suffering from episodes (发作) of the illness during much of their lives. For others, depression has a first onset (起病) in late life - even for t