要除去CaCl2溶液中混有的少量HCl，加入过量下列物质，其中最合理的是（ ）
A．CaCO3
B．Ca（OH）2
C．CaO
D．AgNO3
A、碳酸钙能和盐酸反应生成氯化钙，并且过量的碳酸钙不溶于水，可以用过滤的方法从氯化钙溶液中分离出来，故此项正确．
B、氢氧化钙也能和盐酸反应生成氯化钙，但过量的氢氧化钙会与氯化钙溶液混合，带入新的杂质，故此项错误．
C、氧化钙能和盐酸反应生成氯化钙，但过量的氧化钙会与水反应生成氢氧化钙，会带入新的杂质，故此项错误．
D、硝酸银和盐酸反应生成氯化银沉淀和硝酸，故不能除去氢离子，此项错误．
故选A
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| I was on my lunch break in the city, enjoying a salad at an outdoor cafe, when a shabby homeless lady came walking towards me.She was yelling and __1__ everyone who walked past her for spare __2__ and she looked like a mess.My __3__reaction was fear...to close off and hope she didn't come near me, but she did.I was on the phone and when she __4__yelling, I said, "I'm on the phone, " in the nicest way I could, assuring myself what she needed was a lesson in __5__.She walked away, mumbling (自言自语), "I'm __6__you.I'm sorry, I'm sorry.I'll leave." And she turned the corner.__7__, I would feel relieved or satisfied, but something in me couldn't __8__.Without another thought, I looked in my __9__for the spare change I had.Even I started searching through my entire purse, the pockets, everything-for all of the change I could __10__find to give. I got up and walked towards this lady and gave her all I __11__.She held my hand and said, "Thank you!" Her hand was __12__and dirty, but I didn't mind __13__her hand.I wanted to be there for her for some reason, when normally I would __14__the other way.She looked at me and said, "Will you touch my face?" And for some reason, I did.I put my hand on her cheek and she started to __15__.I could __16__it was as if she had not been touched by a loving, soft hand in ages, __17__, and so I held it there, trying to __18__her with my heart open.It was powerful.She thanked me and walked away quietly.And I walked away with an open heart, trying to__19__sense of what had just happened.It changed something in me and has made me want to be a __20__person to the people I meet during my day. | ||||
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In this section you will find after each of the passages a number of questions or unfinished statements about the passage, each with 4 ( A, B, C and D) choices to complete the statement. You must choose the one which you think fits best. The time for this section is 75 minutes.
| Questions 1-5 are based on the following passage. Sen. John F. Kerry’s 11-day mini-campaign on the theme of national security appears unlikely to produce sensational headlines or seize the country’s attention—which is, on balance, to his credit. At a moment when the crisis in Iraq dominates the national discussion, Mr. Kerry is resisting the temptation to distinguish himself from President Bush with bold but irresponsible proposals to abandon the mission, even though that course is favored by many in his party. Nor has he adopted the near-hysterical rhetoric of former vice president A1 Gore, who has taken to describing Iraq as the greatest strategic catastrophe in American history and calling US handling of foreign detainees an "American gulag. " Instead, Mr. Kerry is in the process of setting out what looks like a sober and substantial altemative to Mr. Bush’s foreign policy, one that correctly identifies the incumbent’s greatest failings while accepting the basic imperatives of the war that was forced on the country on Sept. 11, 2001. In his opening speech on the subject Thursday, Mr. Kerry reiterated one of the central tenets of Mr. Bush’s policy: Lawless states and terrorists armed with weapons of mass destruction present "the single greatest threat to our security. " He said that if an attack on the United States with unconventional weapons "appears imminent I will do whatever is necessary to stop it" and "never cede our security to anyone"—formulations that take him close to Mr. Bush’s preemption doctrine. Yet Mr. Kerry focused much attention on the president’s foremost weakness, his mismanagement of US alliances. The Bush administration, he charged, "bullied when they should have persuadeD． They have gone it alone when they should have assembled a team. " Not only is the truth of that critique glaringly evident in Iraq and elsewhere, but Mr. Kerry is also right to suggest that repairing and reversing the damage probed will require a new president. Though Mr. Bush has belatedly changed course in response to his serial failures in Iraq, there is no evidence that he would pursue a more multilateral foreign policy if reelected． Mr. Kerry’s promise to "launch and lead a new era of alliances for the post 9/11 world" nevertheless does not add up to a strategy by itself. Tensions between the United States and countries such as France, Germany and South Korea predate George W. Bush and will not disappear if he leaves office; leaders in those nations have their own ambitions to challenge or contain American power. Strong alliances require a common strategic vision—and the vision offered so far by Mr. Kerry is relatively narrow. His Thursday speech focused on combating threats and on reducing dependence on Middle East oil; this week he will set out policies to block the spread of nuclear weapons. But he has had little to say about the good that the United States should seek to accomplish in the worlD． In an interview Friday, the candidate stressed that he has set out the "architecture" of his foreign policy and will talk more about goals and values in coming weeks. Thus far he has spoken more about protecting American companies and workers from foreign competition—something that hardly promotes alliances—than about fostering democracy in the Middle East or helping poor nations develop. The emerging Kerry platform suggests that ultimately he would adopt many of the same goals as Mr. Bush. In his latest speech he rightly warned of the terrible consequences of failure in Iraq and, like Mr. Bush, embraced elections and the training of Iraqi security forces as the best way forwarD． His proposal for a U. N. high commissioner represents a slight upgrade on the deference already given by the White House to U. N. representative Lakhdar Brahimi; his call for a NATO- led military mission already has been aggressively pursued by the Bush administration, with poor results. There are, in fact, few responsible alternatives to the administration’s course. Mr. Kerry’s argument is that he has a better chance of making it work. It’s not a bold offer to voters—but it’s probably the fight one. |
The second paragraph suggests that______.
A．Mr. Kerry and Mr. Bush both support the war on terrorism
B．Mr. Kerry and Mr. Bush have very different views on national security issues
C．Mr. Kerry prefers a more sober and substantial foreign policy than Mr. Bush
D．Mr. Kerry has nothing new to offer in his opening speech