Since the launching of the first artificial ________ in 1957, thousands of “man-made moons” have been rocketed into(飞速进入) the Earth’s orbit.
举一反三
- Man has been polluting the earth from the time he first made fire, washed his clothes in the river and threw his waste on the ground. When land was used up or water became (1) , man moved on to another place.
- Ever since human beings have ______ the earth, they have made use of various kinds of tools. A: dwelt B: inhabited C: lingered D: perched
- _____ man first made use of electricity is not exactly known yet. A: Since B: Although C: Whether D: When
- The tortoise as far as I know has been on earth for thousands of years.
- Email has been one of Google’s features since the first day of the company.