Each of these objects need
their full transparent histories told
before anyone enters the fray.请问上述 need their histories told 是否类似于 have something
done?谢谢!
The problem is that catalysts and membranes have been expensive until recently.请问这里catalysts and membranes是最近才开始变贵,还是从以前到最近一直都是这么贵,还是说以前一直贵,但最近不贵了?还请教 until recently 是否有多种不同的用法?