下列关于直升机和旋翼机的论述，正确的是（）A、均能进行垂直飞行 B、均使用旋翼产生推力

The 2012 London Olympics had enough problems to worry about. But one more has just been added - a communications blackout caused by solar storms.

After a period of calm within the Sun, scientists have detected the signs of a flesh cycle of sunspots that could peak in 2012, just in time for the arrival of the Olympic torch in London.

Now scientists believe that this peak could result in vast solar explosions that could throw billions of tons of charged matter towards the Earth, causing strong solar storms that could jam the telecommunications satellites and interact links sending five Olympic broadcast from London.

"The Sun's activity has a strong influence on the Earth. The Olympics could be in the middle of the next solar maximum which could affect the functions of communications satellites," said Professor Richard Harrison, head of space physics at the Rutherford Appleton Laboratory in Oxfordshire. 

At the peak of the cycle, violent outbursts called coronal mass ejections (日冕物质抛射) occur in the Sun's atmosphere, throwing out great quantities of electrically-charged matter. " A coronal mass ejection can carry a billion tons of solar material into space at over a million    kilometres per hour. Such events can expose astronauts to a deadly amount, can disable satellites, cause power failures on Earth and disturb communications," Professor Harrison added. The risk is greatest during a solar maximum when there is the greatest number of sunspots.

Next week in America, NASA is scheduled to launch a satellite for monitoring solar activity called the Solar Dynamics Observatory (SDO), which will take images of the Sun that are 10 times clearer than the most advanced televisions available.

The Rutherford Appleton Laboratory helped to make the high-tech cameras that will capture images of the solar flares (太阳耀斑) and explosions as they occur.

Professor Richard Hold away, the lab's director, said that the SDO should be able to provide early warning of a solar flare or explosion big enough to affect satellite communications on Earth "If we have advance warning, we'll be able to reduce the damage. What you don't want is things switching off for a week with no idea of what's caused the problem," he said.

1. The phrase "communications blackout" in paragraph 1 most probably refers to      during the 2012 Olympics.

A. the extinguishing of the Olympic torch

B. the collapse of broadcasting systems

C. the transportation breakdown in London

D. the destruction of weather satellites

2. What can be inferred about the solar activity described in the passage?

A. The most fatal matter from the corona falls onto Earth.

B. The solar storm peak occurs in the middle of each cycle.

C. It takes several seconds for the charged matter to reach Earth.

D. The number of sunspots declines after coronal mass ejections.

3. According to the passage, NASA will launch a satellite to _________.

A. take images of the solar system         B. provide early warning of thunderstorms

C. keep track of solar activities            D. improve the communications on Earth

4. Which of the following might be the best title of the passage?

A. Solar Storms: An Invisible Killer

B. Solar Storms: Earth Environment in Danger

C. Solar Storms: Threatening the Human Race

D. Solar Storms: Human Activities to Be Troubled

Ⅰ度松动的牙松动方向是（）

A.仅有唇（颊）舌向松动

B.唇（颊）舌向及近远中向均有松动

C.近远中向及垂直向均有松动

D.唇（颊）舌向及近远中向松动，并伴有垂直向松动

E.以上均不对

影响氧化反应的因素有哪些？

在企业内部()对药品质量具有裁决权

A．企业主要负责人

B．质量检验机构

C．销售部门

D．质量保证机构

E．质量管理机构

国务院反垄断执法机构决定实施进一步审查的，应当自决定之日起（）内审查完毕，作出是否禁止经营者集中的决定，并书面通知经营者。

A.30日

B.60日

C.90日

D.120日