有一面积为100 cm2的金属环,电阻为0.1 Ω,环中磁场变化规律如图乙所示,且磁场方向垂直于环面向里,在t1~t2这段时间内:
- The TV program Voice of Youth is really great.
- I think so. It ______ the hearts of lots of fans since it started.
下列属于特异性免疫的是( )