[单选题] 提问人:匿名网友 提问时间:2021-08-24

He has also included symbols to show which ions are nutrients, and which are common in soil or water. ________.


A .There have been many attempts to redesign the periodic table since Dmitri Mendeleev drew it up in 1871.
B .And the size of element’s symbol reflects how much of it is found in the Earth’s crust.
C .Railsback has still ordered the elements according to the number of protons they have.
D .Raisback has listed some elements more than once.

提问人:匿名网友 提问时间:2021-08-24

参考答案(由小熊题库网聘请的专业题库老师提供的解答)

请点击↑↑↑ 查看官方参考答案 按钮

习题解析

请点击 查看官方参考答案 按钮

您可能感兴趣的题目


1 .The weather of the Caribbean Sea is almost always warm and sunny.Sandy beaches line the coasts of many islands. ________. Many tourists arrive on cruise ships.

A They are Cuba,Puerto Rico,Jamaica,and Hispaniola. B The Caribbean Islands are known by several names. C Some of these islands are no more than tiny slivers(小片)of exposed coral. D This is why millions of tourists visit the islands each year.

题型: 单选题 提问时间: 2021-08-24

2 .More and more Americans are living alone. Some live alone because of divorce or the death of a partner. ________. According to a recent U.S. census (人口普查), 25 percent of all households in the U.S. are made up of just one person.

A It seems that many grown-ups today are realizing that childhood dream. B He says, “I like being by myself.” C However, even more people are living alone because they have chosen to. D There’s more pressure to get married nowadays.

题型: 单选题 提问时间: 2021-08-24

3 .Some 20,000 tons of antibiotics are used in the European Union and the US each year. More than half are give to farm-animals to prevent disease and promote growth. ________.

A The warning comes from a researcher in Switzerland who looked at levels of the drugs in farm slurry. B The drugs could be getting into our food and water. C Many drugs given to humans are also excreted unchanged. D But recent research has found a direct link between the increased use of these farm...

题型: 单选题 提问时间: 2021-08-24

4 .Mexico's current lack of funds is also partly due to oil. The country has rich oil fields and a few years ago, when oil was expensive, Mexico was selling large quantities of oil to the USA and earning a lot of money. ________. However, the price of oil then dropped, and Mexico has been left owing enormous sums of money and with not enough income from oil sales to pay back the loans.

A But those ruins are in danger of being seriously damaged by pollution. B Scientists estimate that about one millimeter of stone is worn away every twelve years. C At others the painted surfaces inside temples are lifting and flaking off and the stone is being eaten away. D The government was there...

题型: 单选题 提问时间: 2021-08-24

5 .As part of their study, the researchers used a special machine to take action photos of the students' brains. ________. This is the same part of the brain that becomes active when good readers read. This activated brain area appears to include a structure that helps people recognize familiar written words quickly.

A Do you have difficulty reading in class? B The pictures showed an increase in activity in the back of the brain on the left side. C As part of the study, 37 struggling readers received special tutoring. D By the end of the school year, these children could read faster than before.

题型: 单选题 提问时间: 2021-08-24

7 .When do people decide whether or not they want to become friends? During their first four minutes together, according to a book by Dr. Leonard Zunin. In his book, "Contact: The first four minutes," he offers this advice to anyone interested in starting new friendships: ________. A lot of people's whole lives would change if they did just that.

A That is not the time to complain about one's health or to mention faults one finds in other people. B Every time you meet someone in a social situation, give him your undivided attention for four minutes. C It is not the time to tell the whole truth about one's opinions and impressions. D He is ea...

题型: 单选题 提问时间: 2021-08-24

8 .The typical person living alone is neither old nor lonely. ________. The majority of these people have chosen to live alone. They are responding to decreasing social pressure to get married and have a family.

A This is a dramatic change from the extended families of just a couple of generations ago. B The growing number of women with good jobs has done much to increase the number of people living alone. C There's more pressure to get married nowadays. D In fact, a quarter of the 23 million single people ...

题型: 单选题 提问时间: 2021-08-24

9 .Bees are flying insects closely related to wasps and ants, and are known for their role in pollination (授粉)and for producing honey and beeswax. ________ The best-known bee species is the European honey bee, which, as its name suggests, produces honey, as do a few other types of bee.

A There is only one queen in a hive. B Every bee does a job without being told. C There are nearly 20,000 known species of bees. D Bees do not like ice and snow.

题型: 单选题 提问时间: 2021-08-24

10 .But Bali starlings are only found in a small area on the island of Bali in Indonesia. They live in the tall grasslands near the coast. ______ Today there are only 14 left in the wild on a single reserve. More than half of their habitat was converted into farmland, and forest plantation. Many of them were captured and sold as pets.

A We should take measures to protect them. B Bali starlings are very beautiful birds. C They grow fast because of a protein rich diet of insects. D In 1984, there were only 150 birds left in the wild.

题型: 单选题 提问时间: 2021-08-24

 
如有问题 请联系客服
  • 客服微信