An analyst does research on the reclassification of non-current assets. A company reclassifies a non-current asset from held-for-use to held-for-sale. At that time, the asset's carrying value is greater than its fair value less costs to sell, and the company most likely recognizes:（）

A. a gain.

B. a loss.

C. neither a loss nor a gain.

样品在放置期间，待测组分浓度的影响因素是（）

A.生物因素

B.化学因素

C.生物、化学和物理因素

D.生物和物理因素

E.物理因素