-
Energy independence" and its rhetorical (修辞的) companion "energy security" are, however, slippery concepts that are rarely though through.
出自-2014年6月阅读原文
-
This slippery slope of eroding ethics and bigger risks leads only to disaster.
出自-2011年12月阅读原文
-
The company spent the last five years developing solar panels that are only about a quarter of an inch thick and are strong enough to stand up to heavy highway traffic without breaking or making the roads more slippery.
2017年12月四级真题(第二套)听力 Section A