UC知道新概念英语L62两个语法小问题
来源：百度知道 编辑：UC知道 时间：2024/06/23 03:40:40
这课学习的主要是过去完成时和过去完成进行时
课文中有两个句子的为什么用这个时态不太明白。
课文原文：
Firemen had been fighting the forest for nearly three weeks before they could get it under control. A short time before, great trees had covered the countryside for miles around. Now, smoke still rose up from the warm ground over the desolate hills. Winter was coming on and the hills threatened the surrounding villages with destruction, for heavy rain would not only wash away the soil but would cause serious floods as well. When the fire had at last been put out, the forest authorities ordered several tons of a special type of grass-seed which would grow quickly. The seed was sprayed over the ground in huge quantities by aeroplanes. The planes had been planting seed for nearly a month when it began to rain. By then, however, in many places the grass had already taken root. In place of the great trees which had been growing there for centuries patches of green had begun to appear in the blackened soil.
一共俩问题：<
课文中有两个句子的为什么用这个时态不太明白。
课文原文：
Firemen had been fighting the forest for nearly three weeks before they could get it under control. A short time before, great trees had covered the countryside for miles around. Now, smoke still rose up from the warm ground over the desolate hills. Winter was coming on and the hills threatened the surrounding villages with destruction, for heavy rain would not only wash away the soil but would cause serious floods as well. When the fire had at last been put out, the forest authorities ordered several tons of a special type of grass-seed which would grow quickly. The seed was sprayed over the ground in huge quantities by aeroplanes. The planes had been planting seed for nearly a month when it began to rain. By then, however, in many places the grass had already taken root. In place of the great trees which had been growing there for centuries patches of green had begun to appear in the blackened soil.
一共俩问题：<
第一个问题好说：你要注意了，草覆盖郊外是过去的过去的事情，但是在大火之后，草已经没有持续覆盖地面了，因为大火把草烧毁了，这就是为什么后面文章中说的the forest authorities ordered several tons of a special type of grass-seed which would grow quickly，所以当然不能用保持持续的动作的过去完成进行时。
至于第二个题目：我认为遵照全篇都是过去完成时态，所以这里使用过去完成时态要比过去时要更好点~~
1.这段文章说的是失火了，树木都不见了。你说的这个句子是说没火灾时的情形。是过去的事。你之前的理解很正确，但这对后面无影响也没持续啊！
2.瞬间动作确实不能用进行时。
第一句是强调它的覆盖面积大。不是强调动作吧
第二句这是一个主句，他的从句用过去完成进行时。
1、表示过去就已经完成了，当然用过去完成时了。
2、这个同上。