答案是A

41. GWD31-41

Even though Clovis points, spear points with longitudinal grooves chipped onto

their faces, have been round all over north America ,they are named for the

new Mexico site where whey were first discovered in 1932

1)  Even though Clovis points , spear points with longitudinal grooves chipped

onto their faces, have been found all over north America, they are named

for the new Mexico site where they were first discovered in 1932.

2)   Although named for the new Mexico site where fist discovered in 1932. 

Clovis points are spear points of longitudinal grooves chipped onto their

faces and have been found all over north America .

3)   Named for the new Mexico site where they have been first discovered in

1932. Clovis points, spear points of longitudinal grooves chipped onto the

       faces, have been found all over north America .

4)   Spear points with longitudinal grooves that are chipped onto the faces ,Clovis

  points , even though named for the new Mexico site where first discovered

in 1932, but were found all over north America .

5)   While Clovis points are spear points whose faces have longitudinal grooves

chipped into them ,they have been found all over north America ,,and named

for the new Mexico site where they have been first discovered in 1932

我觉得A中,两个 they指代不一样,第一个 their指spear points第二个they 指Covis points