不是纵隔内结构的是（）
A.心包
B.心脏
C.心脏大血管
D.气管
E.脊柱胸段
参考答案：E
原核生物中具有GTP酶活性的翻译起始因子是
A．IF1
B．IF2
C．IF3
D．eIF1
E．eIF2
________it was ________so many elephants marching along the street.
A．How great fun; to see
B．What a great fun; seeing
C．What great fun; to see
D．How great a fun; to see.
