They are wasting resources, for example, time, energy and money.
上面這句話不錯，只是轉折詞for example不妥當;應該這樣：
They are wasting resources. For example, they use too much time, energy and money.
不然就要換一換轉折詞，改用such as或like：
They are wasting resources, such as time, energy and money.
不管任何語言，轉折詞(transitional words)都扮演著一個重要角色，就是：承先啟後，使句子緊湊，段落相吸，對文章結構，有良性作用。但是有些人幾乎沒有採用轉折詞的習慣，結果文句鬆散，上下文七零八亂，應該避免。
現在把主要轉折詞，分類列下，供大家參考。
Ⅰ表示尤有進者的意思：
Again, also, then, besides, further, furthermore, moreover, next, in addition等，如：
① Jason teaches diligently. Besides, he writes a lot.
② English is a useful language. For one thing, it is an official language in the UN. Then, it is widely used in business, science and technology.
Ⅱ表示反意見：
But, however, still, yet, after all, for all that, in spite of, on the contrary, on the other hand等，如：
③ Jim is intelligent but lazy.
④ Singapore is not a big the contrary, it is very small.
