照样子写词语，再选两个词语造句。  

1．   圆滚滚                                                                      

        清清楚楚                                                                     

2．                                                                                                     

某法测血钙的回收率为95.7%，用该法测定真值为2.5mmol/L的标本（）。

A.该法有4.3%的恒定误差

B.测定值约为2.39mmol/L

C.测定误差为0.11mmol/L

D.该法有4.3%的比例误差

E.该法有4.3%的随机误差