where have you been?we have been looking for you everywhere.
根据where have you been?我们知道“we”已经结束了【寻找“you”的动作,而 have been looking for you everywhere是在“你出现在我们面前之前发生的动作”.have been doing sth是【现在完成进行时】,表示动作发生在过去,没有间断一直延续到现在.
i(worked out)a teaching plan in my office.为什么这里不填have been working out.had been working out; had been work out
因为worked out是一般过去时,单纯表动作发生在过去；have been working out是现在完成进行时,跟上面的 have been looking for you everywhere一样是现在完成进行时,表示的概念是一样的；.had been working out是过去完成进行时,它表示的概念是动作发生在【过去的过去】,是一个相对时态,即：相对【某个过去时间】来说更先前的动作,而且也是一直没有间断持续到【过去】；没有 had been work out这种时态.
如果我帮到了你,那么talking and laughing,the children (found)themselves near the mountain这样填对吗？还有before主句是一般现在时，从句也用一般现在时吗？主句用现在完成时，从句应该用什么时态呢？那么talking and laughing, the children (found) themselves near the mountain这样填对吗？还有before主句是一般现在时，从句也用一般现在时吗？主句用现在完成时，从句应该用什么时态呢？这里的talking and laughing是两个并列的现在分词，做状语，修饰动词found，意思是：他们一路说笑，不知不觉他们【发现】他们走近了大山。before的用法一般【不用于现在时】，从句也不用于一般现在时。用在含有before的主从复合句中，一般在从句中使用【一般过去时】，主句中使用【过去完成时】。例如： Lily had written some letters before she went out shopping. 有时，也可以在从句中用过去完成时，主句中用一般过去时，这样就可使描述更为生动。试比较： We got to the station before the train had left. 火车尚未开动之前，我们就到了车站。 We had got to the station before the train left. 火车开出之前，我们就【已经】到了车站。主句用现在完成时，从句应该用什么时态呢？主句用现在完成时态，【状语从句】可以用现在时态中的：一般现在时态、现在进行时态如：1.When he gets to school ，the class has already begun.2.When I am trying to work out the problem，he has already done it.