题干

把少量下列物质分别加入水中,充分搅拌,不能得到溶液的是(  )

A:泥沙

B:纯碱

C:食盐

D:蔗糖

上一题 下一题 0.0难度 选择题 更新时间:2017-05-18 09:16:43

答案(点此获取答案解析)

A

同类题1

阅读理解

    Greece's finance minister says his country's financial situation is “terribly urgent” and the crisis could come to a head in a couple of weeks. Yanis Varoufakis gave the warning after eurozone finance ministers met in Brussels to discuss the final €7.2bn tranche(援助资金) of Greece's €240bn EU/IMF bailout(紧急援助).

    Ministers said Greece had made “progress” but more work was needed.

The Greek government is struggling to meet its payment obligations(责任).Earlier, Greece began the transfer of €750m (£544m, $834m) in debt interest to the International Monetary Fund - a day ahead of a payment deadline.

    “The liquidity(资产流动性) issue is a terribly urgent issue. It's common knowledge, let's not beat around the bush,” Mr Varoufakis told reporters in Brussels. “From the perspective of timing, we are talking about the next couple of weeks.”

    Greece has until the end of June to reach a reform deal with its international creditors. Its finances are running so low that it has had to ask public bodies for help. The crisis has raised the prospect that Greece might default(违约) on its debts and leave the euro.

    In a statement, the eurozone finance ministers said they “welcomed the progress that has been achieved so far” in the negotiations,” but added: “We acknowledged that more time and effort are needed to bridge the gaps on the remaining open issues.” Eurogroup chairman Jeroen Dijsselbloem said there had to be a full deal on the bailout(紧急财务援助) before Greece received any further payments. “There are time constraints(限制;约束) and liquidity constraints and hopefully we will reach an agreement before time runs out and before money runs out.” he said.

    There had been fears that Greece would default on its IMF debt repayment due on Tuesday. However, a Greek finance ministry official was quoted as saying that the order for repayment had been executed(实施) on Monday. Almost €1bn has been handed over to the IMF in interest payments since the start of May.

    It is unclear how the government came up with the funds, but the mayor of Greece's second city Thessaloniki revealed last week that he had handed over cash reserves in response to an appeal for money.

同类题4

“胃肠感冒”在医学上又称“呕吐性上感”,主要是由一种叫“柯萨奇”的病毒引起的,同时伴有细菌性混合感染.它的发病症状主要是:呕吐、腹泻、发热等.

(1)胃部因病菌或其他毒性物质进入,通过非条件反射导致胃体肌肉收缩,将胃内容物排出体外,该反射弧中效应器由____ 组成.神经冲动在离体神经纤维上以局部电流的方式双向传导,但在上述反射弧中,传导方向是单向的,总是由胞体传向____ .剧烈而频繁的呕吐引起大量消化液的丧失,造成水分大量流失,使机体的内环境渗透压升高,下丘脑的____ 会感知此变化,并促使下丘脑合成和分泌____,作用与肾小管和集合管,促进原尿中水分的重吸收,维持内环境的稳定.

(2)当体内有炎症时会出现发热现象,这有利于吞噬细胞和杀菌物质等转移到炎症区,抵御病原体的攻击,此过程属于机体免疫系统的第____ 道防线.在体温升高的过程中,机体产热量____(填“大于”、“小于”或“等于”)散热量.

(3)机体感染柯萨奇病毒后,通过____ 免疫产生抗体与病毒发生特异性结合.有人提议注射疫苗预防该疾病,注射疫苗预防疾病的机理主要是使机体产生____,提高机体的免疫能力.免疫调节不仅积极应对外来抗原的入侵,同时也随时应对体内的衰老和癌变的细胞,这说明免疫系统具有____ 功能.