8.已知集合U=RU=RU=R,A={x∣x2−4x+3⩽0}A=\{x\vert x^{2}-4x+3\leqslant 0\}A={x∣x2−4x+3⩽0},B={x∣1<log2x<2}B=\{x\vert 1<\log _{2}x<2\}B={x∣1<log2x<2},则((( )))