抗原
参考答案:抗原-刺激机体产生抗体或致敏淋巴细胞(1),发挥免疫效应(1)
To the joy of the parents,their only son is now ________ to achieve his goal.[ ]
A.making every effort
B.making all effort
C.make an effort
D.sparing no efforts
相比而言车辆发动机润滑油哪种价格钱高。()
A.矿物润滑油
B.半合成润滑油
C.全合成润滑油
D.都一样