某合金(仅含铜、铁)中铜和铁的物质的量之和为ymol,其中Cu的物质的量分数为a

题型:选择题

问题:

某合金(仅含铜、铁)中铜和铁的物质的量之和为y mol,其中Cu的物质的量分数为a,将其全部投入50mLbmol-L-1的硝酸溶液中,加热使其充分反应(假设NO是唯一的还原产物).下列说法正确的是(  )

A.若金属有剩余,在溶液中再滴入硫酸后,金属又开始溶解

B.若金属全部溶解,则溶液中一定含有Fe3+

C.若金属全部溶解,且产生336 mL气体(标准状况),则b=0.3

D.当溶液中金属离子只有Fe3+、Cu2+时,则a与b的关系为:b≥80y(1-

a
3)

考点:单质铁单质铜氧化亚铜氧化铜氢氧化铜
题型:选择题

以下哪项不符合病毒性肠炎()

A.多发生于秋季

B.常有上呼吸道症状

C.中毒症状明显

D.大便无腥臭味

E.大便蛋花样

题型:选择题

You may know your mother, but how well do you really know Mother’s Day? Cards, flowers, sales, TV specials, and a day off for someone who really deserves it —those are what probably come to mind for many people when they think of Mother’s Day. But there’s more about the story.

The earliest Mother’s Day celebrations were held during spring in Ancient Greece. The celebrations honored Rhea, the Mother of the gods. During the 1600s, England celebrated a day called Mothering Sunday. On this day even servants (仆人) were given the day off to spend with their families. A mothering cake was even served with the family meal.

In the U.S., Mother’s Day began in 1872 when Julia Ward Howe, who wrote the words of the famous song The Battle Hymn of the Republic, suggested it as a day devoted to peace. But it didn’t really become popular until 1907 when Anna Jarvis started a campaign (运动) to honor her own mother. She believed that mothers could help people get over the pain they experienced during the Civil War. The U.S. isn’t alone in devoting a day to its mothers. Many other countries including Denmark, Finland, Italy, Turkey, Australia, Japan, and Belgium also celebrate their Mother’s Day in May. Other countries honor their mothers at different times of the year.

Learning more about Mother’s Day and celebrating Mother’s Day is important, but probably not as important as understanding what your own mother, or grandmother, or aunt has really done for you. And that should certainly be appreciated more than one day in a year.

小题1:What is the passage mainly about?

A.The reason why people celebrate Mother’s Day.

B.How people honor mothers.

C.The history of Mother’s Day.

D.Mother’s Day in different countries.小题2:Where was the earliest Mother’s Day celebrated?

A.In Ancient Greece.

B.In the U.S.

C.In England.

D.In Italy.小题3:According to the third paragraph, we know that _____.

A.Julia Ward Howe composed a song about Mother’s Day

B.American people started to celebrate Mother’s Day in 1907

C.Anna Jarvis attached great importance to mothers

D.Mother’s Day celebrations are held in different times in the U.S. every year小题4:The last paragraph tells us that ______.

A.all the people should celebrate Mother’s Day

B.only mothers are honored on Mother’s Day

C.understanding mothers’work is more important than just celebrating Mother’s Day

D.people should make every day a Mother’s Day

题型:选择题

关于内脏性疼痛的描述不正确的是

A.定位不准确
B.常引起腹肌紧张
C.痛觉迟钝
D.范围不明显
E.缓慢、持续

题型:选择题

运输途中,站、车发现无货签的行李包裹,应查清到站,补全货签或编制纪录,运行至()

A.中途站

B.下站

C.到站

题型:选择题

我国地方猪种性成熟早,一般在()月龄、体重25-30千克时达到性成熟。

A、1-2

B、2-3

C、3-4

D、4-5

更多题库