题目

下列没有具有细胞壁的选项是（）       A．                       花粉                            B． 肌细胞                  C．   大肠杆菌       D． 酵母菌 答案：B—Do you know Tina well?          —Yes. She and I _____ friends since we met last summer. [     ]A. have made    B. were    C. have been