【简答题】CO是大气污染物之一。用氯化钯(PdCl 2 )可以测定微量CO的存在,该反应的化学方程式为PdCl 2 +CO+H 2 O==Pd↓+2HCl+CO 2 。若反应后得到Pd的质量为1.06g,则测得CO的质量为多少克?(已知Pd的相对原子质量为106)
【判断题】高速铁路接触网的定位装置包括定位器和接触管。( )
【单选题】相对而言,用样本指标去推断相应的全及指标,点估计的可靠性比区间估计( )。
【单选题】The first debate was____________to have been held on Tuesday.
【单选题】相对而言,用样本指标去推断相应的全及指标,点估计的可靠性比区间估计( )。
【单选题】PD Co is deciding whether to replace its delivery vans every year or every other year. The initial cost of a van is $20,000. Maintenance costs would be nil in the first year, and $5,000 at the end of...
【单选题】The first debate was____________to have been held on Tuesday.
【单选题】相对而言,用样本指标去推断相应的全及指标,点估计的可靠性比区间估计的( ) 。
【单选题】The first debate_____ have been held on Tuesday.