理工类考试辅导：补全对话Image Martian Dust
NASAs Phoenix Mars Lander1 has taken its first-ever picture of a single particle of rusty Martian dust with one of its microscopes. The dust particles of dust were shown at a higher magnification than anything outside of Earth that has been imaged before. The rounded particle measured only about one micrometer， or one millionth of a meter， across.
Taking this image required the highest resolution microscope operated off Earth2 and a specially designed device to hold the Martian dust，" said Tom Pike， a Phoenix science team member from Imperial College London3. "We always knew it was going to be technically very challenging to image particles this small4.
The device that imaged the dust speck is called an atomic force microscope， which maps the shape of particles in three dimensions by scanning them with a sharp tip at the end of a spring. The atomic force microscope can detail the shapes of particles as small as about 100 nanometers. And this wont be the last dust particle that Phoenix will image5. "After this first success， were now working on building up a portrait gallery6 of the dust on Mars，" Pike said.
Dust exists everywhere on Mars， coating the surface and giving it its rusty red color. Dust particles also color the Martian sky pink and feed storms that regularly envelope the planet. The ultra-fine7 dust is the medium that actively links gases in the Martian atmosphere to processes in Martian soil， so it is critically important to understanding Mars environment8， the researchers said.
The $420-million Phoenix mission is analyzing the dust and subsurface ice layers of Mars arctic regions to look for signs of potential past habitability. The particle seen in the atomic force microscope image was part of a sample scooped by the robotic arm from the "Snow White" trench and delivered to Phoenixs microscope station in early July.
词汇：
image v. 绘……的图像 scan v. 扫描
magnification n. 放大 subsurface adj. 地面下的
micrometer n. 微米 habitability n. 居住性
resolution n. 分辨率，清晰度 scoop v. 挖
map v. 绘制……的地图 trench n. 沟
注释：
1. NASAs Phoenix Mars Lander： 美国国家航空航天局的凤凰号火星登陆器
2. off earth ： 地球之外
3. Imperial College London ： 伦敦帝国学院
4. image particles this small： 描绘如此之小的微粒。image particles this small是口语的说法，其意思是image such small particles/image particles which are so small.
5. And this wont be the last dust particle that Phoenix will image： 这不会是凤凰号扫描图像的最后的尘粒。本句的言外之意是：科学家将会收集更多的火星微粒进行扫描。
6. portrait gallery： (火星尘粒)图像陈列馆
7. ultra-fine：超小的
8. it is critically important to understanding Mars environment： 火星尘粒对于了解火星环境是极端重要的。it指代上一句的dust，而to是介词，所以后接动名词 understanding.
练习：
1. The dust particle on Mars is the smallest particle that has been imaged outside of Earth.
A. Right B. Wrong C. Not mentioned