Although two-cycle motorcylces use unleaded gas, their engines are not so efficient in the first place, and they still produce a lot of pollution.是什么意思_Although two-cycle motorcylces use unleaded gas, their engines are not so efficient in the first place, and they still produce a lot of pollution.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句