题目内容：

A mechanical bicycle lock, like a U-lock, should be attached to a solid and immobile object like a rack（架子）to ensure safety. However, these racks are quite rare and popular, thus often occupied and although a bicycle lock prevents the bike from being carried away, as it fixes single parts like the frame or the wheels, other parts can be dismounted. Therefore an electronic system, consisting of several sensors, can extend the range of protection with only few components and less effort.

The ‘RFID Bikealarm’ is a motion sensitive electronic alarm system that is attached to the rails of a bike saddle（座椅）. Featuring omnidirectional（全方位）movement sensing to detect tiny movements or speeding-up and a small whistle emitting >120dB alarm sound to scare off potential thieves by arousing attention.

The internal microcontroller uses a complex computer program to distinguish between a serious theft and harmless shaking movement as it senses and adapts to the environment. The usage is quite simple: identify yourself by holding the RFID tag close to the case to lock or unlock the alarm system signaled by feedback sounds. The RFID-technology is predestined for achieving this simple and secure interaction because it doesn’t require any complex system, interaction or other devices—just a small tag.

The ‘RFID Bikcalarm’ is meant to be a useful add-on to mechanical bicycle locks as it massively extends the range of protection with few components. It is low-cost, durable and easy to use. The internal battery can be charged by USB.

1.What does the underlined word “dismounted” in Paragraph 1 most probably mean?

A. fixed up    B. found out

C. taken away    D. locked up

2.Which of the following shows the right position of the RFID Bikealarm on a bicycle?

A.     B.

C.     D.

3.What will happen when someone steals a bike with the RFID Bikealarm?

A. Noises will be made.    B. The bike will be locked.

C. The thief will be identified.    D. Messages will be sent to the owner.

4.Which of the following is a feature of the RFID Bikealarm?

A. It uses complex parts.    B. It needs a rack to prevent bike theft.

C. Its high price scares away its buyers.    D. It works together with a mechanical lock.