问题 选择题

下列对实验结果的推测正确的是(  )

A.某无色溶液中滴加无色酚酞试液,溶液不变色,则该溶液一定是酸性溶液

B.某物质中滴加稀盐酸,生成无色气体,证明该物质中一定含CO32-

C.某溶液中滴加BaCl2溶液,生成不溶于稀HNO3的白色沉淀,则该溶液中一定含有SO42-

D.某无色溶液中滴加NaOH溶液后加热,生成使湿润的红色石蕊试纸变蓝的气体,证明该溶液中一定含有NH4+

答案

A、酚酞遇中性和酸性溶液均不变色,所以某无色溶液中滴加无色酚酞试液,溶液不变色,该溶液不一定是酸性溶液.

B、金属(氢前)与碳酸盐遇盐酸均会生成气体,所以某物质中滴加稀盐酸,生成无色气体,不能证明该物质中一定含CO32-

C、某溶液中滴加BaCl2溶液,生成不溶于稀HNO3的白色沉淀,因为氯化钡提供了钡离子与氯离子,所以该白色沉淀可能是硫酸钡也可能是氯化银,因此溶液中不一定含有SO42-也可能含有银离子.

D、铵根遇碱会生成氨气,氨气能使使湿润的红色石蕊试纸变蓝,这是铵根离子鉴定的常用方法,所以某无色溶液中滴加NaOH溶液后加热,生成使湿润的红色石蕊试纸变蓝的气体,证明该溶液中一定含有NH4+

故选D.

阅读理解

People with bigger brains ftend to score higher on standardized tests of intelligence, according to new study findings.

However, the study author Dr Michael A.McDaniel of the Virginia Commonwealth University in Richmond emphasized that these findings represent a general trend, and people with small heads should not automatically believe they are less intelligent. For instance, Albert Einstein’s brain was “not particularly large”, McDaniel noted. “There’s some relationship between brain size and intelligence on the average, but there’s plenty of room for exceptions,” he said.

Interest in the relationship between brain size and intelligence grew in the1830s,  when German anatomist(解剖学家) Frederich Tiedmann wrote that he believed there was “an unquestionable connection between the size of the brain and the mental energy displayed by the individual man”. Since that statement, scientists have conducted numerous studies to determine if Tiedmann’s  assertion was, in fact, correct. Most studies have looked into the link between head size and intelligence. More recently, however, researchers have published additional studies on brain size and intelligence, measured using MRI scan(核磁共振成像扫描).

For his study, McDaniel analyzed more than 20 studies that looked into the relationship between brain size and intelligence in a total of 1,530 people. The studies showed that on the average, people with larger brain volume tended to be more intelligent. The relationship between brain volume and intelligence was stronger in women than men, and in adults than in children. McDaniel notes in the journal Intelligence.

McDaniel is not sure why the relationship was stronger for adults and women. “Other research has shown that women, on the average, tend to have smaller brains than men, but score just as well—if not higher—in tests of intelligence,” he said.

McDaniel insisted that the relationship between brain size and intelligence is not a “perfect” one. “One can certainly find lots of examples of smaller-sized people who are highly intelligent,” he said, “But, on the average, the relationship holds.”

小题1:. What does the text mainly talk about?

A.MRI scans are applied to intelligence.

B.On the average, a bigger brain means higher IQ.

C.Dr McDaniel did well in his intelligence study.

D.Scientists are interested in Tiedmann’s idea.小题2: By mentioning Albert Einstein, the writer wants to show    .

A.Albert Einstein was intelligent

B.the result of intelligence test was false

C.being hard working is more important than intelligence

D.brain size doesn’t necessarily decide the level of intelligence小题3: The underlined word “assertion” in Para. 3 probably means “    ”.

A. experiment   B. statement  C proof      D. demand

小题4: After Frederich Tiedmann wrote his article,    .

A.many scientists agreed with him

B.numerous studies have failed to prove his idea

C.MRI scan became popularly used

D.lots of researchers were interested in the connections between head size and intelligence小题5: According to the text, Dr McDaniel’s study    .

A.proves Tiedmann’s idea was completely true

B.shows women are smarter than men

C.involves many studies and a lot of people

D.explains why people with smaller brains are clever

单项选择题