2. To make a photo look as if it were taken on a traditional camera, you can ________.

　　A. use a filter

　　B. use a "slider" system

　　C. add some film effects

　　D. make minor changes to the app

　　3. Who would most probably click the links?

　　A. People who want to use Afterlight.

　　B. People who are interested in Instagram.

　　C. People who hope to learn about Android.

　　D. People who need to learn about some apps.

　　B

　　On Friday, December 11, 2015, I visited NASA's Lyndon B. Johnson Space Center in Houston, Texas.

　　My first stop was the Space Food Systems Laboratory, where I met with Ben O'Neil, a food scientist. He makes and packages food for astronauts in space. I got to taste mixed fruits, Italian veggies, beef ravioli, blueberry cobbler, shrimp cocktail, and a mango peach smoothie. Space food tastes like the food we eat on Earth. That's because it is. Space food is made out of ingredients you can find at your grocery store. A special process is applied to keep the important nutrients that space explorers need to stay healthy.

　　Next, I met with astronaut Terry Virts, who recently spent six months living and working on the International Space Station (ISS). "At an early age I wanted to be a pilot，" Virts told me. "But after reading the book Apollo, I decided to be an astronaut." I asked if he was scared the first time he went into space. "No，" he said. "I was more concerned with not letting anyone down. Now, thinking back, I should have been afraid because of the 40,000 pounds of explosives under me at take­off."

　　As my visit continued, I learned about NASA's new Orion spacecraft that is designed to take astronauts farther into space than ever before. I talked to Stu McClung, Orion's spacecraft engineer, and toured the model spacecraft. McClung showed me the control panel (控制面板) and allowed me to strap into a launching seat. He also showed me a video that explains what happens when a spacecraft re­enters Earth's atmosphere.

　　My last meeting was with Lucien Junkin, a NASA robotics engineer who helps to create rovers and humanoids. Rovers are space exploration vehicles and humanoids are robots that do work or activities in space similar to what humans do on Earth. I even got to drive a rover.

　　4. When tasting food provided by Ben O'Neil, the author ________.

A. felt sad about astronauts in space