能加速学习，延长记忆的内分泌激素是（）
A.5-羟色胺
B.促肾上腺皮质素
C.去甲肾上腺素
D.肾上腺素
E.血管加压素
参考答案：E
The special dance，Gangnam Style，is ________ popular all over the world and was even performed in the White House.
A．steadily
B．firmly
C．increasingly
D．regularly
试简述液化气罐的专用附件及其作用？
