问题
判断题
N,N-二乙基-1,4苯二胺(DPD)分光光度法测定水中游离氯时,如加入的DPD试剂与游离氯反应产物所显深红色很快裉尽,是因为水样中游离氯浓度较高,被氧化而显色的试剂随即又被游离氯漂白,此时应将样品稀释后再测定
答案
参考答案:对
N,N-二乙基-1,4苯二胺(DPD)分光光度法测定水中游离氯时,如加入的DPD试剂与游离氯反应产物所显深红色很快裉尽,是因为水样中游离氯浓度较高,被氧化而显色的试剂随即又被游离氯漂白,此时应将样品稀释后再测定
参考答案:对
Choose the proper phrase from the box and complete the sentence with the correct form. | ||||||||||
1. Liu Qian is a popular magician and has shown how wonderful magic is. ________, more teenagers begin to get interested in magic after watching his performances. 2. The boss ________ the staff is on holiday in Sanya. No one can help you. 3. At school we can try lots of interesting optional courses on Friday afternoon, _________ Chinese medicine and English drama. 4. The teacher often tells the little kids to _________ the toys by themselves. 5. The cleaner cleared the snow on the road _________ until he was sent to hospital. 6. —What do you _________ the Chinese New Year? —It's lively and cheerful. 7. He refused my suggestion _________ but later he changed his mind. 8. I bought Twilight series as soon as they _________. 9. He has made _________ new friends since he moved to the village. 10. I like bungee jumping very much. _________ I'm crazy about it. |