测定某药物的炽灼残渣，坩锅在700℃炽灼至恒重后重量为30.2080g，加入样品后共重31.2030g，照炽灼残渣检查法处理、炽灼后，称得重量为30.2092g，试计算炽灼残渣的百分率？
查看答案
测定某药物的干燥失重，在105℃干燥至恒重的称量瓶重18.2650g，加入样品后共重19.2816g，再在105℃干燥至恒重后重19.2765g，试计算干燥失重？
试题在前，备选答案在后，每组5题，每组题均对应同一组备选答案，每题只有一个正确答案
Which one of the following expressions is NOT giving directions?
A. Could you tell me where it is?
B. It is at the end of Burton Road.
C. Walk to the end of the corridor.
Which one of the following expressions is giving directions?
A. Excuse me, I am looking for the library.
B. Am I right?
C. Go upstairs.
微信支付 
支付宝支付