澳门的标志性建筑是:()。
A.妈祖阁
B.大炮台
C.大三巴牌坊
D.安平古堡
参考答案:C
_____ well prepared you are, you still need a lot of luck in mountain climbing. [ ]
A. However
B. Whatever
C. No matter
D. Although
某一通风排气系统在t=20℃,P=101325Pa的环境下运行,排出空气中NQ2浓度为1000mg/m3,则把该浓度用比摩尔分数表示应为()kmolNO2/kmol空气。
A.4.87×10-4
B.4.65×10-4
C.4.27×10-4
D.4.98×10-3