Tenses Worksheet For Class 9 CBSE
Fill in the blanks with the appropriate form of the verb given in the brackets.
A spacecraft orbiting Mars …………………….. (finds / has found / have found) huge deposits of ice at the south pole of the planet. Scientists said that if the ice deposits …………………………. (were / are / have been) in liquid form, they would be enough to blanket the entire planet in water.
The scientists ………………………. (used / have used / were using) the joint Nasa-Italian Space Agency radar instrument on the European space Agency Mars Express spacecraft to gauge the thickness and volume of ice deposits at the Martian South Pole. The ice deposits, up to 2.3 miles thick, are under a polar cap of white carbon dioxide and water. Scientists already ……………………… (are knowing / know / knew) that water ……………………….. (is existing / has existed / exists) in frozen form at the Martian poles, but this research produced the most accurate measurement of just how much there …………………………. (is / was / has been).
Answers
A spacecraft orbiting Mars has found huge deposits of ice at the south pole of the planet. Scientists said that if the ice deposits were in liquid form, they would be enough to blanket the entire planet in water.
The scientists used the joint Nasa-Italian Space Agency radar instrument on the European space Agency Mars Express spacecraft to gauge the thickness and volume of ice deposits at the Martian South Pole. The ice deposits, up to 2.3 miles thick, are under a polar cap of white carbon dioxide and water. Scientists already know that water exists in frozen form at the Martian poles, but this research produced the most accurate measurement of just how much there is.