细菌的遗传物质包括()。
A.核质和质粒
B.核质、质粒和中介体
C.核质、质粒和前噬菌体
D.核质和前噬菌体
E.核质、中介体和前噬菌体
参考答案:C
Other businesses, such as insurance companies, are more concerned with acquiring a central position so that they are ______ to the urban population.
A.beneficial
B.relevant
C.independent
D.accessible
()工件在一道工序中通过一次装夹后完成的那一部分工艺过程。