Seven countries signed a treaty binding each of them to performspecified actons on a ceratin fixed date, with the actions of eachconditional on simultaneous action taken by the other countries. Eachcountry was also to notify the six other countries when it hadcompleted 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)oneof the countries might not be required to make any changes or take anysteps in order to comply with the treaty, whereas all the othercountries are so required (C)each country might have a well-founded excuse,based on the provision, for its own lack of compliance. (D)thetreaty specified that the signal for one of the countries to initiateaction was notification by the other countries that they had completedaction. (E)there was ambiguity with respect to the date after which all actionscontemplated in the treaty are to be complete. 逻辑应该是互相等待以致死锁，我选的是D，答案是C。难道是因为D是说明原因而非一中可能性？就错在这里吗？
In several nineteenth-century paintings the marble buildings of the Acropolis in Athens are portrayed as being reddish, but the buildings do not now appear reddish. The marble’s natural color cannot have changed since the nineteenth century, so the paintings must not be showing the color of the buildings as they actually appeared. Which of the following, if true, most seriously undermines the argument above?
A The Acropolis can be clearly seen from virtually any location within the city of Athens. B Tinyplantscalledlichensliving on marble can cause the marble to appear reddish. C Many nineteenth-century artists strove for true- to-life accuracy in every detail of their paintings. D Some types of marble are naturally reddish, whereas other types are greenish or white. E Not all nineteenth-century paintings of the Acropolis show the marble buildings as being reddish. 答案：(B)那么C呢？？？
