用于发展及评价参考方法和一级标准品的方法称为()

A．指定参考方法

B．决定性方法

C．参考方法

D．常规方法

E．经典方法

根据首字母及汉语提示,完成下列单词的拼写,使句意通顺。

小题1:Hainan  is a  good place to go s________.

小题2:Tom and Sam are twins,but there are some d__________between them.

小题3:F_______ is quite important to everyone .We all need friends.

小题4:You should practice more to __________(提高)your English.

小题5:I am _________(口渴的)and I  world like something to drink.