鸟卵胚胎发育所需要的营养物质主要来自于[ ]
A．卵黄
B．卵白
C．胚盘
D．气室
答案：A
These comments are not directly ___________ to this enquiry.
A．concerned
B．relevant
C．different
D．involved
CB-CO5A甲烷指示警报器的用途是什么？
