过去完成式与下列三种句型连用。
1 had been doing + when ··· +动词简单过去式：
本课：The planes had been planting seed for nearly a month when it began to rain.
例：I had been reading when I heard steps outside. 我一直在读书之时，突然，我听到外边有脚步声。
比较：I was reading when I heard steps outside. 我正在读书之时，突然听到外边有脚步声。
2 had been doing + before···+动词简单过去式：
本课：Fireman had been fighting the forest fire for nearly three weeks before they could get it under control.
例：He had been working in a factory for years before he got this job. 在他得到这个工作之前，他一直在一家工厂里工作有多年了。
3 He had been working for that for the last ten years. 十年来，他一直受雇于那家公司。（讲这句话时，是指五十年代，或六十年代的情况）
如：Empress Ci-Xi had been living in the Summer Palace for the last two months. 两个月以来，西太后一直住在颐和园。（叙述过去情况）
上面两句话不能用since代替for the last···
但可以说：He had been working for that firm for five years (since his marriage)
4 had lived···before he returned to··· 在回到······之前就曾经住在······
例如：
1)No sooner had he gone to sleep than the telephone rang once more. (他刚睡着，电话铃又响了。)
2)He had no sooner reached the door than he came back.(他刚走到门口就走回来了。)
3) He had hardly had time to realize what was happening when she pushed him out of the room.(他还来不及弄清发生了什么事，突然她把他推出房间去。)
4) He acted as if he had done something great.(他一举一动好象他做了一件什么了不起的事似的。)
5) I had written him three letters before he wrote back.(在他回我信之前我曾写给他三封信。)
6) They had lived in many countries before they settled in England.(在他们定居英国之前，他们曾在许多国家主过。)
7) I had hardly opened the door when he hit me on the head.(我刚开门他就一拳打在我的头上。)
8) We had hardly arrive when it began to snow.(我们刚到就开始下雪了。)
9) Hardly had we arrived when we had to go back.(我们刚到就不得不返回。)
2.no sooner···than, 这个 than 很多人好象都喜欢写 then , 似乎认为 then 比 than “说得通”。可是这毕竟是固定的搭配，不能一自己的想象来代替。
3. continually 与 continuously，前者是有间隙停顿的“不断”，后者则是有连续性的“不断”。例：
1)The baby is continually crying.婴儿不断地哭。
2)The river flows continuously.河水不断地流。

----------------------VOCABULARY-------------------
get···under control 把···控制住
for miles around 方圆有五英里
rise up 升起
come on 临近
threaten···with 以···相威胁；对···具有···的威胁
not only···but···as well 不但···而且(用到as well不能再用 but also，只能用 but)
be put out 被扑灭
special type of 特种的
in huge quantities 大量地
take root 扎根
in place of 代替
for centuries 有好几个世纪了
patches of 一块一块的

==============《 After the Fire 》=============
___火灾之后____
Firemen had been fighting the forest fire for nearly three weeks before they could get it under control.
{ 消防队员在把火灾控制住之前一直与森林大火搏斗了近三个星期。}
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.
{不久前，大树覆盖了这个乡村方圆数英里的地方。现在，在一些荒芜的小山上，灼热的地面仍然冒着浓烟。冬天快到了，这些小山对周围的村庄具有毁灭性的威胁，因为大雨将不仅冲走土壤，并将引起严重的水灾。}
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.
{当火灾终于被扑灭后，森林管理当局定购了好几吨特种速生草籽，飞机把这些草籽大量地撒在地面上。}
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.
{飞机一直在播种草籽已近一个月，突然天开始下雨了。不过到天开始下雨前，在很多地方，草早已扎下了根。在那里一直生长了好几个世纪的大树虽被烧毁，但在这片被熏黑了的土地上，代之而起的却是一块块绿色的草地。}