题目

-Can we make the plan a week later? -No，we can’t________ doing it because Clean-Up Day is only a week away from now． A．put off                 B．put up                  C．set up                    D．put on 答案：A吞噬细胞对细菌抗原的吞噬、加工处理和呈递过程如图所示。下列叙述正确的是（ ）A．吞噬细胞特异性地吞噬细菌抗原B．溶酶体参与抗原的加工处理过程C．加工处理后的抗原可直接呈递给B淋巴细胞D．抗原加工处理和呈递过程只存在于体液免疫