下列图形可由平移得到的是（   ）

Problems relating to people’s livelihood have been the focus of the government, especially _______ ­­Premier Wen Jiabao included them in his government work report last year.

如图，梯形ABCD的两条对角线交于点E，图中面积相等的三角形共有____对．

$\left(\frac{\text{1}}{\text{2}}+\frac{\text{1}}{\text{3}}+\frac{\text{1}}{\text{4}}\right)\times 12$ ＝(   )

下图为人体血液流过肾脏后某物质含量的变化情况，则该物质最可能是（    ）