1. Tesla,an American firm that has done much to help electric cars shed their museli-munching image,is struggling to meet demand for its mid-market Model 3 (though that has not stopped it announcing plans to build electric lorries as well).

特斯拉，一家做了大量工作以帮助他们的电动汽车改变”咀嚼麦片“的形象的汽车制造公司，目前正在努力满足市场对热销中的III型电动车的需求（尽管这并未阻止他们宣布也要制造电动卡车的计划）。

本句中 help electric cars shed their museli-munching image 是什么意思？

帮助他们的电动车改变像是嘴里咀嚼着燕麦片的外观。

shed: vt, 除掉

museli: 浓麦片

munching: 动词”吃、咀嚼“的动名词

museli-munching image: 嘴里嚼着燕麦片的形象/外观=image of munching museli

2. One is that combustion engines are not very efficient at turning the energy in their fuel into motion.Instead,a great deal of it ends up wasted as heat.

end up后接介词短语、副词、现在分词或过去分词作方式状语，表示以什么方式结束/终结。本句中过去分词短语wasted as heat作end up的方式状语。