除有特别规定外，任何煤气设施均应保持（）操作。
A、正压
B、负压
参考答案：A
6060600是______位数，在这个数中，最左边的6表示6个______．
In this factory, suggestions often have to wait for months before they are fully _____.
A．admitted
B．acknowledged
C．absorbed
D．considered
