某男性患者，14岁，左侧磨牙关系近中尖对尖，右侧磨牙关系完全近中，前牙反2mm，开4mm

前牙开为

A:正常 B:Ⅰ度 C:Ⅱ度 D:Ⅲ度 E:Ⅳ度

No matter how hard he worked, ______. ( )

A:he could not do any better B:and he could not do any better C:so he could not do any better D:but he could not do any better

Today a pilot is totally dependent on what the air traffic controller on the ground tells him. He can’t see enough to be safe. Flight watch is an instrument intended to help him.
On a screen in front of the pilot, there will be a map of the (21) around the plane. The pilot’s own (22) level or height and his own plane at the center of the (23) will show up. On the map any other planes in the airspace will (24) as spots of light with "tails" showing the direction of their light. The flight watch map is (25) for the other planes are not shown at their true (26) , but at their distances away in flying time. This (27) the problem of fast planes being too far away to be seen (28) likely to make contact in seconds and (29) planes that are close enough to be seen but so slow that there’s no chance of (30) for, say, ten minutes.
The pilot will be able to see on the screen whether another plane’s course conflicts with (31) . The screen will show him the flight number of the other plane, so he can contact air traffic control and ask them about the other plane’s course. Then he can take (32) action if necessary. The screen will show him whether his action puts him (33) from yet another aircraft.
Technically, the (34) will be quite complex. Computers will be necessary on the ground and (35) each aircraft to enable Flight watch to collect data about the plane courses and to calculate the distances between planes. But such small computers are now quite cheap, simple and reliable.

A:space B:screen C:sky D:map

Passage Five
A new kind of radar has been developed for spaceship travelers. A working laboratory model of a new system of radar that makes use of a beam of light is said to be ten thousand times more accurate than the best comparable system of radar that used microwaves.
The model has shown that this radar system, known as laser-doppler radar, can measure with absolute precision speeds varying from spaceship orbital injection (进入) velocities (速度) of five miles per second down to virtual stops--speeds of less than one ten thousandth of an inch per second. According to the scientists who are developing this system, such fine measures of velocity are of prime importance in space missions. In a rendezvous (对接) between two spaceships, or in a landing approach by a vehicle onto an orbiting space station, a bump could rip open a ship’s skin, or a nudge could knock the station out of its orbit.
The light-beam radar, which operates at a frequency of trillions (百万兆) of cycles per second, could easily detect and measure the movement of a vehicle edging up to a satellite space station. A control system using so precise a signal as this would allow a huge vehicle to dock at a space station as lightly as a feather.

A:Rendezvous in Space B:Landing at a Space Station C:New Radar for the Space Age D:Space Navigation

Passage Five
A new kind of radar has been developed for spaceship travelers. A working laboratory model of a new system of radar that makes use of a beam of light is said to be ten thousand times more accurate than the best comparable system of radar that used microwaves.
The model has shown that this radar system, known as laser-doppler radar, can measure with absolute precision speeds varying from spaceship orbital injection (进入) velocities (速度) of five miles per second down to virtual stops--speeds of less than one ten thousandth of an inch per second. According to the scientists who are developing this system, such fine measures of velocity are of prime importance in space missions. In a rendezvous (对接) between two spaceships, or in a landing approach by a vehicle onto an orbiting space station, a bump could rip open a ship’s skin, or a nudge could knock the station out of its orbit.
The light-beam radar, which operates at a frequency of trillions (百万兆) of cycles per second, could easily detect and measure the movement of a vehicle edging up to a satellite space station. A control system using so precise a signal as this would allow a huge vehicle to dock at a space station as lightly as a feather.

A:accuracy ill speed measurement is essential to spaceships B:the speeds of space vehicles will vary C:inaccuracies in measurement could cause accidents in space missions D:a bump could affect the preciseness of the laser-doppler radar

Did he tell you what ______ if he had a chance

A:was he going to do B:he would do C:be had done D:had to do

What is the purpose of the radar reflector?

A:Making objects less visible B:Making echoes weaker on theradar C:Making large echoes smailer D:Making small objects bettervisible

"When radar is set to ships head up display, all fixed targets displayed on the screen will appear to______．

A:track down the screen on a reciprocal heading at the speed ship is moving B:rotate in the same direction as the ship rotates C:make the identification of smaller targets difficult D:allow a certain amount of afterglow of targets"

SWEEP INT on radar panel is the abbreviation of ______．

A:sweep introduction B:sweep interest C:sweep intention D:sweep intensity"