测定水中易释放氰化物时,加热蒸馏在pH为()的介质中、硝酸锌存在下进行。
A.2
B.4
C.7
D.12
参考答案:B
Look and judge. 看图,判断正(T)误(F)。
1.This country is Canada. The capital city of Canada is Canberra. They speak English. ( )
2.This country is the U. K. The capital city of the U. K. is London. ( )
3.This is Tian'anmen Square. It is in Beijing. ( )
4.This is south. South points down. ( )
5.In this country, there are beautiful beaches. The capital city is Ottawa. ( )
从调查入手,充分理解用户业务活动和信息需求,它是系统设计的主要依据,因而结构化方法具有鲜明的______特点。