某食品检出一培养物,其生化试验结果为:H2S-,靛基质-,尿素-,KCN-,赖氨酸+,需进一步作()试验。
A.ONPG
B.甘露醇
C.山梨醇
D.血清学
参考答案:A
.
--- When will you be through with your work, Jones?
--- ______ My boss usually finds something for me to do at the last minute.
A.Who knows.
B.Would you help me?
C.I beg your pardon?
D.Anything the matter?
启动子的作用是什么原核生物启动子的结构特征是什么