部分停电的工作是指哪些工作？

质量为270g的冰熔化成水后，其体积减少了______m³。(ρ_水=1×10³kg/m³， ρ_冰=0.9×10³kg/m³)

Today, over six billion people live on the planet. This means that there are very few places on Earth with no people. One place that has very few people is at the bottom of the Earth. In Antarctica, the icy continent surrounding the South Pole, you will not find anyone who lives there all the time.

First, Antarctica is the coldest place on Earth. For example, it can be –l30℃ in the winter. Humans cannot live in this kind of environment. Because it is so cold, very few plants or animals live there. This means there are no farms and no places to find wild plants or animals to eat.

Second, Antarctica can be dangerous. Many people think that it is safe to travel to Antarctica in the summer months when it is warmer. However, Antarctica is mostly ice, so when it’s summer, the ice melts. When the ice melts, the ice can break. So, people cannot travel around Antarctica during the summer. If the ice breaks, they could fall into the water and die.

Another serious problem in Antarctica is the sun. Because Antarctica is mostly ice, there are no trees so there is no shade. Also, the ground is mostly white ice so the sun bounces off (反射) it. The light from the sky and the light from the ground can burn people’s skin and hurt their eyes. People must be very careful in this situation. For example, they must wear sunglasses to protect their eyes. They must also cover their hands and faces all the time.

Although Antarctica is a tough place to live, explorers have discovered coal in Antarctica. This leads them to believe that Antarctica at one time was a land of swam (沼泽) and forests.

小题1:This text is mainly about _____.

A．the discovery of Antarctica

B．how people travel around Antarctica

C．different animals found in Antarctica

D．why it is difficult to live in Antarctica小题2:We can learn from the text that _____.

A．Antarctica is a place with no animals

B．no people can survive in Antarctica

C．Antarctica is colder than any other continent on Earth

D．the temperature in Antarctica is below zero all the time小题3:When is the most dangerous time to travel around Antarctica?

A．In spring.

B．In summer.

C．In autumn.

D．In winter.

应急预防乙型肝炎有效的免疫制剂是（）

A.HBsAg疫苗

B.胎盘球蛋白

C.丙种球蛋白

D.HBIg

E.人血清白蛋白

腹外斜肌位于腹部的（）

A、前外侧

B、前壁正中

C、深层

D、内侧

国务院常务会议决定，进一步深化行政审批制度改革，使简政放权成为持续的改革行动。深化行政审批制度改革的哲学依据是（）

A.生产关系一定要适合生产力状况

B.社会意识具有相对独立性

C.上层建筑一定要适合经济基础状况

D.人生的真正价值在于奉献