皮皮学,免费搜题
登录
logo - 刷刷题
搜题
【单选题】
听力原文: It was 2:05 in the afternoon. When I entered the classroom, I was surprised to see a video camera. Our class teacher was operating the camera, and my classmates were all talking among themselves slowly. Most of us had never been in front of a video camera before, so we were quite nervous. As for myself, I had once faced one at home. My uncle was shooting when we were celebrating my sister's birthday. But this was completely different. We had to talk about our articles as if we were reading news on TV. The funny thing was that every time I tried to face the camera and talk about my article, I forgot the article and couldn't resist looking down at it. It was a completely different experience for me, thanks to our class teacher. What were the students going to do?
A.
They were going to read their articles before a video camera.
B.
They were going to read news on TV.
C.
They were going to celebrate the writer's sister's birthday.
手机使用
分享
复制链接
新浪微博
分享QQ
微信扫一扫
微信内点击右上角“…”即可分享
反馈
参考答案:
举一反三
【单选题】下列关于蒸馏操作的有关叙述不正确的是( )
A.
蒸馏操作的主要仪器是:蒸馏烧瓶、酒精灯、铁架台、冷凝管、锥形瓶、牛角管、温度计等
B.
蒸馏操作使用的温度计的水银球应插入到液体内
C.
在蒸馏烧瓶内放入少量碎瓷片,目的是防止暴沸
D.
冷凝管进出水的方向是下口进、上口出
【单选题】下列关于蒸馏操作的有关叙述不正确的是(  )
A.
蒸馏操作主要仪器是:蒸馏烧瓶、酒精灯、铁架台、冷凝管、锥形瓶、温度计
B.
蒸馏操作使用的温度计的水银球应插入到液体内
C.
在蒸馏烧瓶内放入少量碎瓷片,目的是防止暴沸
D.
冷凝管进出水的方向是下进上出
【单选题】有关蒸馏操作不正确的是( )。
A.
加热前应加入数粒沸石
B.
蒸馏完毕后应先停止加热后停止通水
C.
应在加热前向冷凝管内通入冷水
D.
应用大火快速加热
【单选题】测定有机化合物的相对分子质量应采用( )。
A.
质谱法
B.
气相色谱法
C.
紫外-可见分光度法
D.
核磁共振波谱法
E.
红外光谱法
【单选题】测定有机化合物的相对分子质量,应采用
A.
气相色谱
B.
质谱
C.
紫外光谱
D.
核磁共振波谱
【单选题】下列关于蒸馏操作的有关叙述不正确的是 [     ]
A.
蒸馏操作主要仪器是:蒸馏烧瓶、酒精灯、铁架台、冷凝管、锥形瓶、温度计等
B.
蒸馏操作使用的温度计的水银球应插入到液体内
C.
在蒸馏烧瓶内放入少量碎瓷片,目的是防止暴沸
D.
冷凝管进出水 的方向是下进上出
【单选题】套间分( )和( )两种
A.
豪华套间           大床间
B.
标准间           商务间
C.
大床间          标准间
D.
豪华套间           标准套间
【判断题】套间分为标准套间和豪华套间两种。
A.
正确
B.
错误
【单选题】下列关于蒸馏操作的有关叙述不正确的是(  )
A.
蒸馏操作的主要仪器是:蒸馏烧瓶,酒精灯,铁架台,冷凝管,锥形瓶,温度计等
B.
蒸馏操作使用的温度计的水银球应插人到液面下
C.
在蒸馏烧瓶内放入少量碎瓷片
D.
冷凝管进出的水的方向是下进上出
【单选题】有关水蒸气蒸馏的操作不正确的是( )
A.
安全管要插入液面以下,但不接触瓶底
B.
T形管的左低(发生器这边低)右稍高(提取这边高),防止冷凝水流入到提取装置中
C.
T形管里的冷凝水, 需在提取过程中把 夹子打开放出来
D.
加热前,先夹上T形管,提取结束先停止加热,再停止冷凝水,最后打开T形管
相关题目:
参考解析:
知识点:
题目纠错 0
发布
创建自己的小题库 - 刷刷题