题目

“生物导弹”是指 A．单克隆抗体                                                      B．杂交瘤细胞 C．在单抗上连接抗癌药物                                    D．产生特定抗体的B淋巴细胞 答案：CSusan’s parents have bought a large house with a swimming pool. It ______　be very expensive. 　　 A. can B. must C. mustn’t D. can’t