Dr. Howard Roffwarg of the University of Texas in Dallas explains. "We know sleep has a function, 【B13】______ we feel it has a function. We can’t put our finger on it, but it must, 【B14】______ in som

A.通常应成对使用。(A)深沟球轴承(B)圆锥滚子轴承(C)推力球轴承(D)圆柱滚子轴承你选择的答案:B[正确]


B.大脑皮质活动的基本形式是条件反射。()


C.隐性课程主要是通过课程教学而获得的知识和技能。


D.关于路由,以下描述不正确的描述是:()