题目

Do you want to be an astronaut? Then “study hard, stay healthy, hold on to your dreams and never give up!” This is what Chinese astronauts Fei Junlong and Nie Haisheng said in a talk with some students. Students were interested in the astronauts’ space lives. They asked questions like “Did you see the Great Wall from space?” Fei and Nie said they didn’t see the Great Wall. But they felt excited when they passed over China, including Taiwan. The island “looked very beautiful, like a jade(翡翠)”. Speaking of their lives beyond the earth, the two astronauts said working together二次函数y=x2+3的图象的对称轴方程是______．