题目

_______ to the discovery of radium, Madame Curie plays an important role in modern science. A. Devoting                                       B. Devoted            C. Being devoted                                D. Having devoted 答案：B如图，在△ABC中，∠ACB=90°，CD⊥AB，垂足为D，下列结论不正确的是（ ）A．∠ACD=∠BB．CD•AB=AC•BDC．CD2=BD•ADD．CB2=BD•AB