In January, 2004, the United States successfully launched “Spirit”, a Mars Exploration Rover, _____ a new milestone in the history of mankind.
The manager said, “Every means _____ tried, but there is no result.”
I was ill that day, otherwise I ____ the sports meet
The buses, ____were already full, were surrounded by an angry crowd.
If we work with a strong will, we can overcome any difficulty, _____great it is.
--- My son is _____ to be seen. Where has he gone? --- I think he _____ in the building.