题目

Diana used to _____ to work ,but now she is used to _______ to work，because the road is crowded and she wants to keep fit .A. drive ,walking B. drive, walk C. driving , walk D. driving ,driving 答案：【答案】A【解析】句意：Diana过去常常开车去上班，但是现在她习惯走着去上班，因为路太堵了和她想保持健康。根据used to do sth 过去常常做某事，be used to doing sth习惯于做某事，be used to do sth被用来做某事，根据句意可知是过去常常开车去上班，但是现在她习惯走着去上班；故选A。下列能说明某细胞已经发生分化的是                                                        （    ）        A．进行ATP合成                                           B．进行mRNA的合成        C．存在血红蛋白                                           D．存在纤维蛋白原基因