A:in
B:on
C:at
This is Mr White's ________ trip to Beijing. He has been there twice before.
给下列问句选择合适的答语。
A. Yes, it is.
B. I'm 1.7metres.
C. I'm 58 kilograms.
D. A pair of sports shoes.
E. I think Mike's are bigger than mine.
(2012·宁波)小科看到妈妈炒的一盘紫色高丽菜(一种紫色的卷心菜)的菜汁呈紫色,后来因为掺了醋变成了红色,在洗盘子时遇到碱性洗涤剂变成黄绿色。下列也能使紫色高丽菜汁呈现黄绿色的物质是( )