绘制圆环时，若将内径指定为0，则会？（）A、绘制一个线宽为0的圆 B、绘制一个实心圆C

（1）（6分）“假酒”中含有一定量的甲醇（化学式为CH₃OH），饮用后会使人视力迅速下降、失明，甚至死亡。请回答：

① 甲醇的相对分子质量为              。

② 甲醇中C、H、O三种元素的质量比为               。

③ 甲醇中氧元素的质量分数为             。

（2）（10分）实验室可用加热氯酸钾与二氧化锰的混合物制取氧气，其反应的化学方程式为：2KClO₃2KCl + 3O₂↑。现加热氯酸钾与二氧化锰的混合物30g，待氯酸钾完全反应后，称得剩余固体的质量为20.4g。求：

① 反应生成氧气的质量是多少？

② 原混合物中氯酸钾的质量是多少？

How the Grand Canyon (大峡谷) was created remains one of the geology’s greatest mysteries. Some evidence suggests that the process was a gradual one in which the Colorado River (which runs through the canyon) slowly cut deeper and deeper into the ground over millions of years. But volcanic rock samples taken from the canyon now suggest that the canyon was down-cut instead.

Down-cutting is when a flood of water rushes over a landscape (地形) with enough force to cut deeply into the ground and leaves behind a canyon. Such a flood is usually released when a natural or man-made dam (堤坝) bursts.

Robert Webb, a research geologist, says natural dams seem to have formed and broken across the Colorado River several times during the last million years. The dams were built when lava(熔岩) from the eruptions of nearby volcanoes flowed into the river. The lava hardened into hard rocks and blocked the river, causing it to back up and form a lake. Each time the lake grew so huge that it broke the rock dam, releasing a flash flood that furthered the down-cutting process and deepened the canyon.

Down-cutting is not just an earthly event. Satellite photos sent back from Mars suggest that the process has happened there, too, say many other researchers.

The photos, taken by the Mars Global Surveyor, indicate that an enormous lake existed on Mars 3.5 billion years ago. The lake spilled into a large nearby hole. One edge of the hole broke, releasing a flash flood that quickly carved out a grand canyon.

The existence of down-cutting on Mars is just one more piece of evidence that the cold, dry planet was once warm and wet.

小题1:In the past, deep canyons were believed to have formed _______.

A．as a result of a sudden break of volcanoes

B．due to river flows over millions of years

C．owing to the burst of artificial dams

D．thanks to our ancestors’ creative work小题2:According to the passage, which of the following statements is TURE?

A．Several volcanoes broke out on Mars directly creating grand canyons.

B．Several great lakes existed on the upper parts of the Colorado River.

C．People built high dams on the upper parts of the Colorado River.

D．The Colorado River crossed the Grand Canyon to form down-cutting.小题3:From the last three paragraphs we learn that _______.

A．there are great lakes on Mars

B．there are active volcanoes on Mars

C．there might be cities on Mars

D．there might be life on Mars小题4:The passage can be titled as _______.

A．Lakes on Earth and Mars

B．The Cause of Lake Formation

C．The Force of Dam Breaking

D．Canyons—Results of Flood Cutting

中药炮制常用的液体辅料有（）

A.酒

B.醋

C.盐水

D.蜂蜜

E.麻油

对金融机构(包括银行和非银行金融机构)买卖基金的差价收入征收营业税。( )

中国移动占有中国无线音乐（）以上的市场份额。

A、40%

B、50%

C、60%

D、80%