寄生在大肠杆菌细胞里的病毒,叫做( )
A:植物病毒
B:动物病毒
C:人体病毒
D:噬菌体
It was a difficult time for the relatives of Missing MH370 passengers when they heard the bad news , but they didn't ________ hope.
禹州市“五城联创”活动如火如荼进行中,正在加强该市生态环境建设.以下措施对创建“五城”不合理的是( )