----- Nội dung ảnh ----- 1. Sputnik I, the first artificial satellite, was 2. NASA prepares its astronauts for a microgravity environment by 3. A mysterious spacecraft has 4. It took less than an hour before the plane began 5. Astronauts ______________ around in space because there is no gravity in space.
Vào quỹ đạo Trái Đất vào ngày 4 tháng 10 năm 1957.
