例句：

　　People should insulate their homes to conserve energy.

　　人們應(yīng)該使住房隔冷以保存能量。

　　We should conserve oil and gas by making full use of other energy sources.

　　我們應(yīng)該通過充分利用其他能源節(jié)約石油和天然氣。

　　Whales carefully conserve their oxygen when underwater in a couple of ways.

　　鯨魚在水下以幾種方式小心地保存它們的氧氣。