题目

小肠与其吸收功能相适应的结构特点是（   ） ①小肠长5—6米                                            ②肠壁上有肠腺 ③有小肠绒毛                                                 ④小肠绒毛内有毛细血管 A．①②④                B．①③④                   C．②③④                   D．①②③ Tony didn’t come to school last week _______he was ill. And ______his illness he missed a lot of lessons.A. because; because B. because of; because ofC. because; because of D. because of; because