21. Recently, there has been a joke about the first Nobel Laureate from mainland China at the ceremony that he had hardly finished introducing himself, “Hello, everyone, I’m Mo Yan from China. ‘Shut up!’ when the whole building turned silent suddenly, “for _______ English.”

A. a                      B. an                            C. the                    D. /

22. Former champion Liu Xiang’s Olympic misery continued when the Chinese athlete crashed at the first barrier ___________ the 110m hurdles, BBC Sports.

A. on                    B. at                                   C. in                    D. for