n.原因( source的名词复数 );[物理学]源;来源;起源;
例句:
Renewable sources of energy must be used where practical.
必须在可行的地方使用可再生能源。
We mustn't presume too much upon the reliability of such sources.
我们不应过分指望这类消息来源的可靠性.
The village obtains all its energy from renewable sources.
这个村子完全利用可再生能源.