怎样采茧？
参考答案：
按上蔟顺序先上先采，采时先摘除死蚕烂茧，再采好茧、次茧、同宫、薄烂等分别存放出售，不得出售混合茧（统茧）。
He _______ for two years. We are still sad about his _______.
A．died, dead
B．died, death
C．has been dead, dead
D．has been dead, death
监测麦康凯琼脂培养基常见的质控菌株是（）
A.福氏志贺菌ATCC12022
B.大肠埃希菌ATCC25922
C.化脓性链球菌ATCC19615
D.肺炎链球菌ATCC6305
E.脆弱类杆菌ATCC25285
