丸化种子、包膜种子检验净度和纯度时需不需要去除包衣?
参考答案:
净度检验和纯度检验时均需去除外衣,即先放入细孔筛中浸水,除去膜衣,置于恒温箱中干燥后进行检验。
A terrible earthquake hit Wenchuan at 2:28 p.m. _______ May 12th. [ ]
A. on
B. in
C. to
D. at
非营利性