In the past decades，the influence of political parties has been

In the past decades，the influence of political parties has been declining _______．
A、so the political parties are no longer important
B、so an independent presidential candidate can win a national election
C、but without the backing of apolitical party, a presidential candidates till can not win
D、so the presidential election has become more unpredictable
【正确答案】：C
【题目解析】：在过去的几十年里，政党的影响力一直在下降，但是没有非政治党派的支持，总统候选人仍然不可能获胜。