标定高锰酸钾标准溶液时，滴定终点溶液呈紫色且1min不褪色。
参考答案：错
You can find whatever you need at the shopping centre, ___ is always busy at the weekend.
A．that
B．where
C．what
D．which
A．+→
B．→+
C．+→
D．→+
+
→
→
+
+
→
→
+
