【Weekly Question】Participate from 3/6 to 3/12/2017 for +2 wealth； +3 to +10 wealth for correct answers

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To increase the popularity of the chemical analysis section, a \"Question of the Week\" campaign has been launched to foster an active atmosphere for technical exchanges while providing rewards in the form of financial benefits to users. 【Weekly Question】Multiple-choice question: When titrating the concentration of an unknown alkaline solution with standard hydrochloric acid solution, if the measured value is lower than the actual value, the possible cause of this error is ( ). A. The conical flask was not rinsed with alkaline solution. B. The acid burette was not rinsed with standard acid solution. C. There were bubbles at the tip of the acid burette before titration, but these bubbles were gone by the time the titration was completed. D. The pipette was washed with distilled water but not rinsed with alkaline solution. Correct answer: D. Post your answer in the reply section; participating in the quiz earns you +2 points. If you get all answers correct, you’ll receive an additional +3 to +8 points. Those who provide a thorough analysis and explanation of the questions or answers (or include detailed calculation processes) will receive extra points as a reward. If your answer is correct and your analysis is accurate, it will be marked as the best reply (or best assistance). Feel free to answer the questions.