一个句子里面只能有一个谓语!如果taken前面加were了,那么这个句子就不止一个谓语了.这个句子的谓语是are,其他两个taken是做photo的后置定语,就是修饰photo的,什么样的photo,卫星拍下来的photo,原句应该是The photographs of Mars (which are )taken by satellite are much clearer than those(which are) taken from the earth,在这里可省略,被动语态就用过去分词,主动就ing形式的,我解释清楚了吗?有点罗嗦