胸内负压与下列哪个因素无关
A．大气压B．肺内压C．肺的回缩力D．胸膜腔的密闭性E．胸廓的向外扩张力
参考答案：E
My brother likes eating very much but he isn’t very ____ about the food he eats.
A．careful
B．cautious
C．particular
D．generous
裸露病毒体的结构中不包括
A．DNA
B．RNA
C．核衣壳
D．衣壳
E．包膜
