新东方old book section6 20题

20. Seven countries signed a treaty binding each of them to perform specified actions on a certain fixed date, with the actions of each conditional on simultaneous action taken by the other countries. Each country was also to notify the six other countries when it had completed its action.

The simultaneous-action provision of the treaty leaves open the possibility that

(A) the compliance date was subject to postponement, according to the terms of the treaty

(B) one of the countries might not be required to make any changes or take any steps in order to comply with the treaty, whereas all the other countries are so required.

(C) each country might have a well-founded excuse, based on the provision, for its own lack of compliance

(D) the treaty specified that the signal for one of the countries to initiate action was notification by the other countries that they had completed action

(E) there was ambiguity with respect to the date after which all actions contemplated in the treaty are to be complete.

请问这道题的意思？为什么会选C,那个“借口”指的是什么呢？为什么不能选B和E

多谢各位指导

我以下就选了C。

每个国家的行动都需要别的国家配合，可是又不知道别的国家倒底在不在做？（如果它自己先做了，别人不做，岂不是无法达到目的）。这就是excuse。