将50℃的饱和碳酸钠溶液升温至60℃,或者温度仍保持在50℃而加入少量碳酸钠,在

题型:选择题

问题:

将50℃的饱和碳酸钠溶液升温至60℃,或者温度仍保持在50℃而加入少量碳酸钠,在这两种情况下均保持不变的是[ ]

A.溶液的质量

B.溶液中Na的数目

C.碳酸钠的溶解度

D.溶液中溶质的质量分数

考点:碳酸钠
题型:选择题

阅读短文,根据短文内容判断所给句子正(T)误(F)。(共5小题,每小题2分)

David got a job in a police station after he left school. He worked there for 42 years and he’ll retire this year. He worked hard in the past 42 years. But he was not a lucky man. Hefailed to catch a thief. He was often sorry for it.

Last weekend, while David's wife was cooking she found there was no salt at home. Soshe asked her husband to buy some. In the shop, David saw a young man taking away awallet from a woman's bag. He walked to him quietly, but the young man noticed David andran away at once. David ran after him. At last the thief ran into a blind alley(死胡同) andDavid caught him.

“Please give me a chance, sir.” said the thief

“Who can give one to me?”said David, “I’ll soon retire and I catch athief for the first time!”

小题1:David worked hard in the past 42 years.

小题2:David was a lucky man, and he often caught thieves.

小题3: Last weekend his wife asked him to buy some sugar.

小题4:A young man was stealing a woman's wallet in a shop

小题5:The young man was the first thief that David caught.

题型:选择题

已知金刚石的密度为ρ=3.5×103 kg/m3,现有一块体积为4.0×10-8m3的一小块金刚石,它含有多少个碳原子?假如金刚石中的碳原子是紧密地挨在一起,试估算碳原子的直径?(保留两位有效数字)

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关于皮肤纤维瘤不正确的是()

A.好发于成年女性

B.常见的发病部位是小腿伸侧

C.圆形或卵圆形坚实结节

D.组织病理分为纤维型损害和细胞型损害两种

E.治疗首选激光治疗

题型:选择题

下列关于对工程项目实施阶段中设备监理大纲、监理规划及监理实施细则的表述中正确的是( )。

A.设备监理大纲是设备监理单位对拟承揽的设备工程项目开展监理工作的总策划

B.设备监理规划应由监理单位技术负责入主持下开展设备工程监理活动的工作计划

C.设备监理规划的编制基础是委托监理合同

D.对于技术复杂、专业性强的设备工程项目应编制设备监理实施细则

E.设备监理实施细则根据设备监理规划,由专业监理工程师编写,并经总监理工程师批准

题型:选择题

呼吸道合胞病毒性肺炎的临床特点是()

A.两肺以喘鸣音为主

B.稽留高热不退

C.尤多见于1岁以内小儿

D.主要病变在支气管及肺泡

E.主要病变在毛细支气管

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