A.自然界中本来没有耐药细菌个体,滥用青霉素才导致耐药细菌出现 |
B.细菌对青霉素进行定向选择,导致青霉素的使用效果下降 |
C.在长期滥用青霉素的环境中,耐药细菌比不耐药细菌更具生存优势 |
D.在抵抗青霉素作用时,细菌体内的某些结构会发生“用进废退”现象 |

同类型试题

y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2


y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2

