二尖瓣狭窄可见到( )A．靴形心B．梨形心C．烧瓶状心D．心尖部矛盾运动E．心浊音界

实验综合。请完成探究花生果实大小的变异（每空1分，共5分）

1、花生中，有的花生长一些，有的花生短一些，我们分别把它们称为大、小花生，花生长度有差异，这种现象，我们称为___________。

2、随机取大、小花生各30粒来做探究，随机取30粒的目的是避免实验的___________

3、测花生的_______轴长度，做好记录。描点连线，画分布图，求平均值

4、比较大、小花生的分布范围和平均值，我们知道，大花生平均值大于小花生平值，说明花生长短的性状受___________控制。

5、小花生之间长度也有差异，说明花生长短的发生也受___________影响。

请认真阅读下列短文,并根据所读内容在文章后表格中的空格里填入一个最恰当的单词.

注意:每个空格只填1个单词.

     There are many destructive (破坏性的) forces when it comes to nature, which have

destroyed whole cities and killed many people. They're really terrible, but they occur somewhat

often, and this is why you see so many charities these days which focus their efforts on helping

people who have been affected by natural disasters.

     While the world is a very beautiful place to live in, there will always be parts of the world

where natural disasters happen more often than in other places, where properties and lives are

destroyed. Only the people who live in the country where tsunamis and earthquakes as well as

other disasters occur experience these, and we can only imagine the suffering that they go through.

     For some people out there, the world is cruel, but they have no choice but to stay where they

are. A lot of the time people simply cannot afford to move away, as they might not be able to get a

job when they leave.

     In 2004, there was a tsunami in the Indian Ocean. A tsunami is a large wave that towers hundreds

of feet into the air, and covers whole areas when it comes crashing down on to dry land. This particular

tsunami was caused by an earthquake that happened in the middle of the sea, shooting the water away

from the ground and towards dry land. This tsunami actually reached thirty meters in height, and was one

of the worst tidal waves the world has ever seen. Over 200,000 people were hurt in the disaster.

     In 2005, we also saw a hurricane happened in the United States. This hurricane was known as

hurricane Katrina, and is perhaps the worst in the history of the world. It happened in 2005 and

destroyed millions of properties in the area. It also took the lives of nearly 2,000 American people.

It was known that for ten days, the wind swept through the area, meaning the most powerful country

in the world became helpless in their attempts to save the people who were affected by the hurricane.

     Finally, in 2008 we saw yet another natural disaster. This time it was a cyclone (旋风), which is

similar to a hurricane but happens in a circular motion (圆周运动). This cyclone Nargis had been

one of the strongest to have ever occurred, reaching a death toll of nearly 150,000 people.

All of these were terrible disasters that were unavoidable.

                                                           Title: Forces of Nature

证实肺栓塞的诊断，肺血管造影术异常应包括哪些（）

A.血管腔充盈缺损

B.造影剂在肺的局部肺泡中存留与显影

C.肺动脉大分支切断征

D.部分肺小动脉分支充填延迟

E.肺动脉呈"切断"征

什么样质量的恒星死亡后形成中子星（）？

A、大于1.44太阳质量，小于3太阳质量

B、小于3太阳质量

C、大于1.44太阳质量

D、大于3太阳质量

刘禹锡《乌衣巷》名句“旧时王谢堂前燕”中的“谢”是指（）

A.谢朓

B.谢灵运

C.谢玄

D.谢安