根据短文理解，选择正确答案。

Down by the salley gardens

my love and I did meet;

She passed the salley gardens

with little snow-white feet.

She bid (请求) me take love easy,

as the leaves grow on the tree;

But I, being young and foolish(傻的),

with her would not agree.

In a field by the river

my love and I did stand,

And on my leaning shoulder(肩膀)

she put her snow-white ______.

She bid me take life easy,

as the grass grows on the weirs(河堰);

But I was young and foolish,

and now am full of tears(眼泪).

下列调查中，须用普查的是（   ）