骨骼都有最适宜的应力范围，下列哪项不会导致骨钙吸收加快（）
A.应力过高
B.应力过低
C.慢跑
D.长期卧床
E.失重
参考答案：C
细菌的某个基因发生了突变，导致该基因编码的蛋白质肽链中一个氨基酸替换成了另一个氨基酸。该突变发生在基因的[ ]
A．外显子
B．编码区
C．RNA聚合酶结合的位点
D．非编码区
．______was known to them all that William had broken his promise______ he would give each of them a gift.
A．As, which
B．What, that
C．It , that
D．It , which
