在回程过程中，对凸轮机构的压力角加以限制的原因是（）

复分解反应是中学化学中常见的一种反应类型。

(1)已知在常温下测得浓度均为0.1 mol·L^－1的下列6种溶液的pH(C₆H₅OH相当于一元弱酸)：

复分解存在这样一个规律：一种较强酸与另一种较弱酸的盐可以自发地反应，生成较弱酸和较强酸的盐，如：2CH₃COOH＋Na₂CO₃=2CH₃COONa＋CO₂↑＋H₂O。若换个角度看，它同时揭示出另一条规律，即碱性较强的物质发生类似反应可以生成碱性较弱的物质。依照该规律，请判断下列反应不能成立的是______________(填编号)。

A．CO₂＋H₂O＋2NaClO=Na₂CO₃＋2HClO

B．CO₂＋H₂O＋NaClO=NaHCO₃＋HClO

C．CO₂＋H₂O＋C₆H₅ONa―→NaHCO₃＋C₆H₅OH

D．CO₂＋H₂O＋2C₆H₅ONa―→Na₂CO₃＋2C₆H₅OH

E．Na₂CO₃＋C₆H₅OH―→NaHCO₃＋C₆H₅ONa

F．CH₃COOH＋NaCN=CH₃COONa＋HCN

(2)根据前述信息判断，浓度均为0.05 mol·L^－1的下列六种物质的溶液中，pH最小的是________(填编号)；其pH等于________(填数值)；pH最大的是________(填编号)。

①C₆H₅OH　②CH₃COOH　③HCN　④HClO

⑤H₂SO₄　⑥HClO₄

(3)一些复分解反应的发生还遵循其他的规律。下列转化都属于复分解反应：

①工业上将石灰乳与纯碱溶液混合可制得苛性钠溶液

②侯氏制碱法中，向饱和碳酸氢铵溶液中加入饱和食盐水可获得小苏打晶体

③蒸发KCl和NaNO₃混合溶液，首先析出NaCl晶体根据上述反应，总结出复分解反应发生的另一规律___________________________________________

将KI溶液和AgCl固体混合搅拌，会观察到的现象是____________________________________，请写出反应的离子方程式______________________________________________

从海陆位置看，以下国家中与我国相似，都具有海陆兼备特征的是（     ）

A．蒙古

B．日本

C．英国

D．印度

公益性岗位开发计划的主要内容包括：申报事由、岗位名称、（）上岗条件、工资待遇等。

A、岗位质量、工作内容

B、岗位数量、工作内容

C、岗位数量、工作纪律

D、岗位职责、工作内容

Of all the employed workers in the United States, 12.5 million are part of a temporary workforce. The United States Bureau of Labor Statistics counts 9.2 percent of workers as those who have______(1) they term "alternative employment arrangements." The government predicts that temporary staffing agencies______(2) experience growth of 49 percent by 2010. If numbers increase at the rate ______ (3), these companies will add 1.9 million new jobs by 2010. That’’s more than any______(4) industry.Temporary workers were the first ones to be affected by the recent economic recession, but they are______(5) to be the first to regain positions as the economy picks up and companies work to rebuild. Employers use temporary workers as a resource because_______(6) offer flexibility and come at a low cost. Many temporaries are categorized as "independent contractors" instead of employees,______(7) allows the employer to avoid______(8) certain taxes. Because they are not required to offer benefits to temporary workers, companies can save a great deal of money by hiring temps. Usually, temporary workers can qualify_______(9) benefits if they work for a staffing company for a certain length of time. Most temps, however, do not continue with one company long______(10) to qualify for them because they regard the position as a step on the ladder to a______(11) position later.According to Richard Wahlquist, president of the American Staffing Association, 75_______(12) of temporary workers hope for transition out of the temporary staffing category______(13) a period of time. Wahlquist finds that temporary workers spend about 11 weeks on various assignments before their______(14) out of the temporary workforce. Many use temporary positions to gain experience and skills______(15) they move on to better jobs. Wahlquist says that the temp workforce as a whole turns______(16) 400 percent each year.Tom Dilworth, research director at the Employment Policies Institute, explains______(17) some workers like having temporary jobs______(18) it affords them a great deal of elasticity with time and everything. Some temps only have a limited______(19) of time to work and temp agencies can help coordinate jobs to fit their schedules. Other sometimes-employees use temporary jobs to get an______(20) to a company from the inside, to get a foot in the door of a certain business or career._______(21) others take temporary positions in hopes their employers will change them over to permanent positions eventually.Nearly all the industries in the United States use temporary workers.______(22) to Tim Costello, coordinator of the North American Alliance for Fair Employment, the growth of temporary labor threatens______(23) job security of permanent workers who fear replacement, as well as the temps who are more accustomed to turnover. He predicts that there will continue to______(24) a gradual shift from permanent employees to contingent staffing, and that such a_____(25) in workplace demographics will "lead to lower wages, poorer working conditions, and more instability."