Astronaut（宇航员）Scott Kelly has been living on the International Space Station（ISS）since March 28, 2015. And just like any other home, the ISS requires some housekeeping, in the form of regular work and repairs.

That is why Kelly and his partner Kjell Lindgren performed activities, outside the station on Wednesday. The operation began at 8：03 am and lasted for more than seven hours. It was the first spacewalk for both men.

The ISS has been in continual use for 15 years, and has hosted over 200 people, including astronauts and private tourists. During their activities, Kelly and Lindgren did basic electrical work, such as attaching new wires that will provide power to docking ports（舱门）on the station. The ports will be used when other people arrive at the ISS. Also, the two astronauts fixed a thermal（防寒的）cover on a key scientific instrument on the station to protect it from the freezing temperatures of space.

As the more senior astronaut, Kelly led the spacewalk. However, Lindgren dealt with some of the more challenging parts of the job as he has longer arms than Kelly.

During a spacewalk, the simplest work becomes a difficult task. Kelly and Lindgren spent months training and practicing for the operation. The preparation began in NASA's Neutral Buoyancy Lab（NBL）. Here astronauts are made to work in an environment similar to the one outside the space station.

Even getting the space suits ready can take days. While each suit is built to fit the astronaut perfectly who will wear it, adjustments（调整）need to be made right up to the time when the spacewalk begins. The adjustments address any change in the astronauts' bodies that have occurred as a result of being in a gravity-free environment.

【小题1】Why did Kelly and Lindgren take the spacewalk?

A．To clean up the ISS.	B．To keep the ISS in good condition.
C．To test their new space suits.	D．To carry out a scientific experiment.

【小题2】What is the main idea of the third paragraph?

A．How the ISS is working properly.

B．Why the docking ports are useful.

C．How the astronauts performed the spacewalk.

D．What the two astronauts did in the spacewalk.

【小题3】Why did Kjell Lindgren do more challenging work than Kelly during the spacewalk?

A．He knew more about the station.	B．He was the leader of the team.
C．He had a longer reach.	D．He had more experience of spacewalk

【小题4】What does the underlined word "address" in the last paragraph mean?

A．Lead to.

B．Belong to.

C．Interact with.

D．Deal with