With the nuclear crisis worsening in Iran, the world's attention is fixed again on  is called the Middle East．

A．which

B．that

C．what

D．it

下列细菌的细胞壁中具有外膜的是（）

A.大肠埃希菌

B.肺炎链球菌

C.金黄葡萄球菌

D.粪肠球菌

E.表皮葡萄球菌