22．Lawrence Craven, a doctor from the USA，is the author of several published reports, one of______ introduced the idea in 1953 ______aspirin could reduce the risk of heart attacks．

A．them; when

B．which; that

C．what; that

D．which; when

刘某与张某之妻有染，张某得知后非常气愤，决定要教训刘某。某晚，刘某穿小路回家，早已等候在那里的张某放出自己训练的狼狗扑向刘某，张某则躲在角落里不动声响。结果刘某被咬成重伤。张某的行为( )。

A．属于作为犯，构成故意伤害罪

B．属于纯正不作为：犯，构成故意伤害罪

C．属于不纯正不作为犯。构成故意伤害罪

D．不构成犯罪