题目

World­famous violinist Itzhak Perlman was stricken with polio as a child.As a result，he wears braces on both legs and walks with the aid of crutches.At_concerts，getting_on_stage_is_no_small_achievement_for_him. He slowly crosses the stage until he reaches his chair.He lays his crutches on the floor，slowly undoes the clasps (扣环) on his legs，puts one foot backward and extends the other one forward.Then he bends down and picks up the violin，puts it under his chin (下巴)，nods to the conductor，and starts to play. One fall evening in 1995，while performing at Avery Fisher第一次世界大战后的“鲁尔危机”发生于 [　　] A.1921年　　　　B.1923年 C.1927年　　　　D.1929年