测设一点的平面位置,可根据不同的实地情况采取不同的方法,下列不能采取的方法为()。
A.直角坐标
B.极坐标
C.距离交会
D.角度交会
参考答案:C
3H2O2+2H2CrO4═2Cr(OH)3+3O2↑+2H2O
(1)其中Cr被______,H2O2作______剂.
(2)反应转移了0.3mol电子,则产生的气体在标准状态下体积约为______.
A few people were killed in the fire, but _____ were saved.
A.the most
B.most of them
C.most of whom
D.most