题干
—There is a hole in your bag?
—I know. I’m going to have it __________.
—I know. I’m going to have it __________.
A：mend
B：mending
C：mended
D：to be mended
答案(点此获取答案解析）
C
的边长为
，
平面
，那么
到对角线
的距离是
10.6 g Na2CO3溶于水配制成500 mL 溶液，从中取出20 mL，该溶液中Na＋的物质的量浓度为