问题补充：
Their clothes were colorful I could not stop taking photos.
A. too…to…
B. so…that…
C. although…but…
D. because…so…
答案：
A. too…to…
(答案→)B. so…that…
C. although…but…
D. because…so…
解析：根据选项可排除CD，因为although不能和but连用，because不能和so连用； too…to…“太…而不能”中to后面跟动词原形，根据I可知，应该排除A；so…that…“如此…以至于”中的that后面跟句子。
