【简答题】在一次课外活动中,某实验小组从实验室制二氧化碳的废液(假设石灰石中的杂质不溶于水,不与其他物质反应)回收氯化钙溶液,小组成员欲将固体和液体分离可采用一方法.小组成员取两分等质量滤液,向其中一份加入碳酸钙粉末无明显现象;再向另一份中加入50g的碳酸钠溶液,恰好完全反应后.震荡、过滤、洗涤、干燥、称量得到lOg白色固体和84.4g滤液.请回答下列问题: (1)题中生成沉淀的化学反应方程式是______...
【单选题】I am preparing for a speech. What topic ______ ?
A.
do you think I should choose
B.
you think I should choose
C.
do you think should I choose
D.
do you think I should have chosen
【单选题】—Do you think you will fail in the math exam? —_________. I am not good at it at all.
【单选题】李さんはこの食堂___食事___来ました。
【简答题】(14分)某中学化学课外活动小组欲探究铁在氯气中燃烧产物的成份、性质和用途,设计了如下实验步骤: (1)用下列实验装置制取干燥纯净的氯气 ①制备并收集得到干燥纯净的氯气,上述各装置按气流从左到右方向连接顺序为 (填仪器接口的字母编号) ②该实验还存在不足之处,应如何改进? (2)某同学将一定量铁粉与Cl 2 恰好完全反应得到一固体物质a,然后通过实验确定其成分。探究过程如下: ①提出假设:(请把下...
【单选题】If you think the price of pork is too high, you _____ as well buy some beef. It depends on you!
【简答题】某中学化学课外活动小组欲探究铁在氯气中燃烧产物的成份、性质和用途,设计了如下实验步骤: (1)用下列实验装置制取干燥纯净的氯气 ①制备并收集得到干燥纯净的氯气,上述各装置按气流从左到右方向连接顺序为______________(填仪器接口的字母编号) ②该实验还存在不足之处,应如何改进?_________________________ (2)某同学将一定量铁粉与Cl 2 恰好完全反应得到一固体物...
【简答题】某中学化学课外活动小组欲探究铁在氯气中燃烧产物的成份、性质和用途,设计了如下实验步骤: (1)用下列实验装置制取干燥纯净的氯气 ①制备并收集得到干燥纯净的氯气,上述各装置按气流从左到右方向连接顺序为 (填仪器接口的字母编号) ②该实验还存在不足之处,应如何改进? (2)某同学将一定量铁粉与Cl 2 恰好完全反应得到一固体物质a,然后通过实验确定其成分。探究过程如下: ①提出假设:(请把下列假设补充...
【简答题】根据首字母提示补全对话。 1. — What c___________ do you need? — I think I need a dress and a pair of shoes. 2. — Where is my key? — Here it is. You can o___________ your door. 3. — What is he doing? — All done, he...
【单选题】听力原文:M:I don't think having big parties is a mistake.I like big parties.I think we should Pay back our friends who have invited us to their parties. W:But big parties are so impersonal.I think we shou...
A.
She feels she has to pay a lot to hold parties.
B.
She feels small parties are impersonal.
C.
She feels big parties are very. personal.
D.
She dislikes many people at home at the same time.