从事（）施工作业，可免办《水上水下施工作业许可证》。A.设置、拆除水上水下设施 B.

下图对人生的描绘

①看到了人生的不同阶段有不同的矛盾②认为人为事物之间的联系是主观的③通过普遍矛盾呈现了人生不同阶段的特殊矛盾④通过多样性的联系展示了人生各个阶段的特点

A．①②

B．①③

C．③④

D．①④

建筑立面图就是南立面图，而侧立面图就是东或西立面图。

—位糖尿病合并糖尿病肾病患者，经饮食控制后，空腹血糖在10～12mmol/L，可先采用上述哪种药物治疗（）

A．D₈₆₀

B．氯磺丙脲

C．胰岛素

D．优降糖

E．降糖灵

气化用煤的性质包括？

The sun today is a yellow dwarf star. It is fueled by thermonuclear reactions near its center that convert hydrogen to helium. The sun has existed in its present state for about 4 billion, 600 million years and is thousands of times larger than the Earth.
By studying other stars, astronomers can predict what the rest of the sun’s life will be like. About 5 billion years from now, the core of the sun will shrink and become hotter. The surface temperature will fail. The higher temperature of the center will increase the rate of thermonuclear reactions. The outer regions of the sun will expand approximately 35 million miles, about the distance to mercury, which is the closest planet to the sun. The sun will then be a red giant star. Temperatures on the earth will become too hot for life to exist.
Once the sun has used up its thermonuclear energy as a red giant, it will begin to shrink. After it shrinks to the size of the earth, it will become a white dwarf star. The sun may throw off huge amounts of gases in violent eruptions called nova explosions as it changes from a red giant to a white dwarf.
After billions of years as a white dwarf, the Sun will have used up all its fuel and will have lost its heat. Such a star is called a black dwarf. After the Sun has become a black dwarf, the earth will be dark and cold. If any atmosphere remains there, it will have frozen onto the earth’s surface.

When the sun becomes a red giant, what will conditions be like on Earth

A．Its atmosphere will freeze and become solid.
B．It will be enveloped in the expanding surface of the sun.
C．It will become too hot for life to exist.
D．It will be nearly destroyed by nova explosions.