【单选题】Speaker A:Could you give me a ride to the conference center? My presentation is in about half an hour.Speaker B;______Have you checked with Bob? He seems to be on his way there about this time.
A.
I'm sorry. Perhaps next time.
B.
I'm glad to. But it's too late.
C.
I'm afraid I am going to the opposite direction.
D.
Excuse me,but I'm going to the conference center.
【单选题】某试样可能含有 H 3 PO 4 、 NaH 2 PO 4 或 Na 2 HPO 4 ,以甲基橙为指示剂,用 NaOH 标准溶液滴定消耗 V 1 mL ,再以酚酞为指示剂,用 HCl 标准溶液滴定,消耗 V 2 mL ,已知 V 1 = V 2 ,试样的组成为
【简答题】已知某试样可能含有 Na 3 PO 4 、 Na 2 HPO 4 、 NaH 2 PO 4 。今取试样 2.0000g ,以 0.5000mol/L HCl 溶液滴定至甲基橙终点,需用 32.00mL 。同样质量的试样,以 0.5000mol/L HCl 溶液滴定至酚酞终点,需用 12.00mL 。求试样中各组分的质量分数。 (Na 3 PO 4 、 Na 2 HPO 4 、 NaH 2 PO 4...
【单选题】下列方式中不可直接用来插入图像的是( )
B.
在【插入】/【常用】面板的【图像】下拉菜单中单击 按钮
C.
在【文件】/【文件】面板中用鼠标选中文件,然后拖到文档中
D.
在菜单栏中选择【插入】/【图像对像】/【图像占位符】命令
【单选题】听力原文:Could you give me a ride home tonight? (A) Sure, when do you finish? (B) That's a relief. (C) I like horseback riding. (15)