请NN看看大全-1-19,20谢谢(因为是同一段话,只好放一起问了,请版主原谅;)

Archaeologists seeking the location of a legendary siege and destruction of a city are excavating in several possible places, including a middle and a lower layer of a large mound. The bottom of the middle layer contains some pieces of pottery of type 3, known to be from a later period than the time of the destruction of the city, but the lower layer does not.

19.   Which of the following hypotheses is best supported by the evidence above?

(A) The lower layer contains the remains of the city where the siege took place.

(B) The legend confuses stories from two different historical periods.

(C) The middle layer does not represent the period of the siege.

(D) The siege lasted for a long time before the city was destroyed.（C）

(E) The pottery of type 3 was imported to the city by traders.

20.   The force of the evidence cited above is most seriously weakened if which of the following is true?

(A) Gerbils, small animals long native to the area, dig large burrows into which objects can fall when the burrows collapse.

(B) Pottery of types 1 and 2, found in the lower level, was used in the cities from which, according to the legend, the besieging forces came.

(C) Several pieces of stone from a lower-layer wall have been found incorporated into the remains of a building in the middle layer.

(D) Both the middle and the lower layer show evidence of large-scale destruction of habitations by fire.（A）

(E) Bronze ax heads of a type used at the time of the siege were found in the lower level of excavation.

这两题我都完全没有思路,恳请牛牛们指点,感激万分!

（路过）原文大意：为确定某一遗址，在土堆的中，下层挖掘。在中层发现属于后期的东东，在下层没发现此类东东。

1）问：以上发现支持哪个以下设想：

C－中层不属于遗址的年代。（因为发现的后期东东）其他的选择无法从原证据中推出。

2）问：下列选择中哪个对原证据可以 Most weaken.(即理解为发现的陶器可能代表遗址的年代）
A)小动物挖洞，物体可能因洞塌陷，掉入洞中。（即挖洞到遗址层，后期的物体因洞塌，掉入遗址层。所以原证据有效。)