莱姆病游走性红斑的表现特点有()
A.圆或椭圆充血性皮损
B.中心部渐趋苍白
C.可充血和皮肤变硬
D.中心有水疱或坏死
E.外缘鲜红色
参考答案:A, B, C, D, E
Alice ______ watches the news round-up, so she knows little about the world. [ ]
A. seldom
B. usually
C. sometimes
D. always
何谓尺寸链最短原则