下图是位于山东省境内的“泰山大观峰摩崖石刻群”,按世界遗产分类标准,你认为泰山应属于
A.文化遗产
B.自然遗产
C.文化与自然双重遗产
D.非物质遗产
答案:C
—Can he work out the maths problem?
—I think ______ hard for him to work it out.[ ]
A. it's
B. that's
C. this is
D. they're
决定和影响心肌传导性的因素是()
A.部分去极化
B.最大复极电位水平
C.动作电位0期除极的速度和幅度
D.静息电位水平