往水样中投加一些化学试剂(保护剂)可固定水样中某些待测组分,经常使用的水样保护剂有各种()、()、和()、加入量因需要而异。
参考答案:酸;碱;生物抑制剂
A company issues $10 million in 8% annual,5 -year bonds, when the market rate is 8.25%. The initial balance sheet liability and liability one year from the date of issue are closest to: Initial liability Liability one year later ()
A. ①
B. ②
C. ③
揭开戊戌维新变法运动序幕的事件:____________________