材料中( )越小,表明其绝热性能越好。
A.热阻
B.导热系数
C.比热容
D.密度
参考答案:B
—I am sorry I _______ my exercise book at home.
— Don’t forget _______ it to school tomorrow.
A.forget; to take
B.left; to bring
C.forgot; to bring
D.left; to take
喉部CT扫描,仰头的目的是()
A.病人舒服
B.头不易动
C.便于定位
D.喉室打开
E.防止下颌骨重叠