题目内容：

A three-year independent investigation into the September 11, 2001 attack on the Pentagon has yielded new eyewitness evidence which, according to the Southern California-based researchers who conducted the investigation conclusively (and unfortunately), establishes as a historical fact that the violence which took place in Arlington that day was not the result of a surprise attack by suicide hijackers, but rather a military black operation involving a carefully planned and skillfully executed deception."

A CNN Reporter at the scene states that there is no evidence that a 757 hit the Pentagon.

　  What hit the Pentagon? A Boeing 757 loaded with passengers and fuel right? Who was on Flight 757? According to the Flight Information there were No Arabs on it. That makes me wonder if Flight 757 actually existed at all.

　　From the pictures and the videos, people can find that there are several doubtful points that need to be taken into consideration, for example the marker line on the grass in the satellite and ground pictures, the different colors of the smoke, the hole which the plane impacted, and the standing pylons (架线塔).

　　Also, from the comparison of the different pictures, people can find some other strange points. For example, the gear (齿轮) is not the matching one. The wreckage of the plane is not the one from the American Airlines. The glass on the pavement of the pole is another doubtful point. The last thing that need considering is about the collapse. One of the gif video shows the plane impacting the Pentagon. The only problem with this video footage is that it has been altered (改变) and can not be fully trusted.

　　These crash photos and videos shown here clearly have been doctored (篡改) and don't even match the physics of what happened. So where is the real video? It leaves me many questions. Is this a missile? It is a real enigma.

1.Where can you possibly read this article?

A．In a newspaper.

B．In a book.

C．On a website.

D．In a magazine.

2.What the word “yielded” mean in the first sentence?

A．given in

B．surrendered

C．given away

D．produced

3.Which of the following doubtful points is not mentioned in the passage?

A．the colors of the smoke	B．the model of the plane
C．the standing pylons	D．the marker line on the grass

4.What is the author’s attitude towards the 911 investigation?

A．Positive.

B．Neutral.

C．Skeptical.

D．Negative.