photovoltaic systems短语¹⁸⁰⁰⁹⁸⁺¹ 基本例句 🌏光伏系统；光电系统；光致电压系统 Who can explain why in the United States solar- thermal systems are much cheaper than photovoltaic systems, while in China the contention is that former is much more expensive than the latter? 谁能解释为什么美国光热发电比光伏发电便宜许多，而在中国却还有光热贵过光伏的争论？64.22.127.100