Lady Gaga has put off her concerts because of the difficulties by the ongoing strikes.
A. causing
B. to be caused
C. caused
D. to cause
网友回答
A. causing
B. to be caused
(答案→)C. caused
D. to cause
解析：考查分词做定语用法。本句中的名称the difficulties与动词cause之间构成被动的关系，故使用过去分词的形式做定语修饰该名词。句意：因为正在进行的罢工导致的困难，Lady Gaga推迟了她的演奏会。B项不定式表示未来。故C正确。