Câu hỏi:

One time in our history, space travel (31) __________ the dream of writers and filmmakers. Thanks to Robert Goddard’s liquid-fuel rocket, space travel is a reality. We now frequently launch rockets, space probes, space shuttles, and satellites into space. Before we talk about different space vehicles, let us look at (32) __________ it takes to launch into space. Space begins about one hundred miles (160 kilometers) above the upper edge earth’s atmosphere. Rockets need engines that are more powerful than jet engines to launch into space. These powerful engines (33) __________ the rocket to overcome two strong forces: Earth’s gravitation pull and air resistance. Goddard proved that rockets with more than one stage could escape earth’s atmosphere and journey into space. A stage is a section of the rocket that (34) __________ the engine or set of engine and liquid-fuel. The first stage needs to contain enough fuel to lift the entire rocket and its payload. The payload or cargo of a rocket may be a satellite (35) __________ scientific equipment or a space shuttle.

One time in our history, space travel (31) __________ the dream of writers and filmmakers.