单选题 The best information in par

A、 5 is that______.A. electricity from the energy of rivers can be producedB. oil and coal are expensive to extract and transportC. hydroelectric power has some advantages over coal and oilD. waterfalls can be constructed by engineers

【正确答案】

【答案解析】[解析] 该段中提到水又一次成为重要的动力资源，通过对比得出水力发电的优势在于自然界不断地使提供动力的水重复使用，而煤和石油都是一次性燃料。可见答案为：C。