（）明确提出了“青年兴则国家兴，青年强则国家强，青年有希望，未来的发展就有希望”的战

某动物细胞中位于常染色体上的基因A、B、C分别对a、b、c为显性。用2个纯合个体杂交得F₁，F₁测交结果为aabbce：AaBbCc：aaBbcc：AabhCc=1：1：1：1。 则F₁体细胞中三对基因在染色体上的位置是 [ ]

A．

B．

C．

D．

数字式液体压强计由薄片式压强传感器和数据采集显示器两部分组成。如图甲所示，将传感器放在大气中调零后，放入浮有圆柱体A的圆柱形水槽底部，用它来测量水槽底受到水的压强。然后在圆柱体A上逐个放上圆板，水槽底受到水的压强与所加圆板个数的关系如图乙所示。

已知圆柱体的底面积S=0.02m²，圆柱体的密度ρ_A=0.75×10³kg/m³。所有的圆板完全相同，圆板与圆柱体A的底面积相等，厚度d =5mm，g取10N/kg。根据以上数据计算，一个圆板的质量m₁与圆柱体A的质量m_A的比值m₁:m_A=______。

以下各项中，Visual Basic不能接收的图形文件是

A．.ico文件

B．.jpg文件

C．.psd文件

D．.bmp文件

A victim of climate change

A polar bear's dead body found on the Arctic island of Svalbard, the northernmost part of Norway, has shocked experts who say climate change may be to blame for the animal’s death.The starved polar bear in Norway was said to be in good health in April when the Norwegian Polar Institute examined and labeled it． However, the animal was reduced to skin and bones by the time a group of explorers came across its body in July．

The bear is thought to have been heading north in a desperate search for sea ice that would allow it to hunt for seals.

"From his lying position in death the bear appears to simply have starved and died where he dropped," polar bear expert Dr. Ian Stirling, a professor at the University of Alberta said, "He had external suggestion of any remaining fat, having been reduced to little more than skin and bone．"

Stirling believes the bear starved to death as a result of a lack of sea ice which the animals use as a platform for hunting seals． That may also explain why the 16-year-old male bear was found about 155 miles north of where it was seen in April．

Arctic sea ice reached a record low in 2012, according to a report released this week by the National Oceanic and Atmospheric Administration that pointed to continued signs of climate change．

The International Union for Conservation of Nature currently classifies polar bears as vulnerable on its Red List of Threatened Species．

小题1:How did Stirling know the reason for the death of the polar bear?

A．By the food he ate

B．By doing further experiments

C．By observing other polar bears

D．By his lying position in death小题2:The underlined word "vulnerable" probably means _____

A．easily hurt

B．difficult to hunt

C．dangerous

D．amazing小题3:What is the author's attitude to the incident?

A．Favorable．

B．Uncaring

C．Doubtful．

D．Concerned小题4:Where does this text probably come from?

A．A novel．

B．A guidebook

C．A news report．

D．An advertisement

某船丙纶缆的周径为2.5cm，其破断强度为（）（K取0.8）

A.1948.0N

B.1947.8N

C.31360N

D.1947.0N