问题补充：
of fans have voted online their favourite singers.
A. Thousand, for
B. Thousand, to
C. Thousands, to
D. Thousands, for
答案：
A. Thousand, for
B. Thousand, to
C. Thousands, to
(答案→)D. Thousands, for
解析：本题考查数词。thousands of表示成千上万的后接可数名词的复数，而for 表示为···。符合题意，故选D。句意：成千上万的粉丝已经为他们喜爱的歌手在网上投票。
