【单选题】The teacher always tells her students that only if __________ hard _________ achieve success.
A.
do they work, will they
B.
do they work, they will
【简答题】纳氏试剂比色法测定水中氨氮时,取水样50.0ml,测得吸光度为1.02,校准曲线的加厚发议程为y=0.1378x(x指50ml溶液中含氨氮的微克数)。应如何处理才能得到准确的测定结果?
【单选题】Bill always does ______ he pleases, without regard to the feelings of others.