求教一道语法题~~~

ghnsvy

While they remove carbon dioxide from the air, conserve soil and water, and house thousands of species, forests also supply potentially valuable pharmaceuticals, and, as sources of building material and firewood, that provide employment for millions worldwide.

pharmaceuticals, and, as sources of building material and firewood, that provide

pharmaceuticals, and sources of building material and firewood, are providers of

pharmaceuticals and, as sources of building material and firewood that are providing

pharmaceuticals and sources of building material and firewood, for providing

pharmaceuticals and, as sources of building material and firewood, provide


这道题选E,原因其实就是大平行  不过我想问的是...and，... 和...，and，...在用法上有没有什么不一样呢？
求点拨！！！

ghnsvy

幻北 发表于 2016-12-14 12:31
A，B，and C，你肯定能明白。A，B and C，and D这种的，你就要看B和C是否是“连在一起的蚂蚱”——就是说 ...

现在才看到不好意思啊

谢谢谢谢！