Tenses Exercise For Class 9 CBSE
Fill in the blanks with an appropriate verb form.
By now, we all know that air pollution …………………….. (is changing / changes / would change) temperatures on Earth. Now evidence from a mountaintop in China ……………………… (is suggesting / suggests / have suggested) that pollution can also change the amount of rain and snow that ……………………… (falls / fall / has fallen) in some places.
Usually, more precipitation ………………………. (fall / falls / is falling) in mountainous places than in flat areas. That’s because air ………………………… (will / can / may) hold a lot of water. When wind ……………………… (blew / blows / has blown) wet air up a mountainside, the air gets colder. This temperature change often ………………………. (force / forces / has forced) water to fall out of the air as rain or snow. In recent years, however, many mountainous areas across the world …………………………. (have received / receive / received) 25 percent less precipitation than normal.
Answers
By now, we all know that air pollution changes temperatures on Earth. Now evidence from a mountaintop in China suggests that pollution can also change the amount of rain and snow that falls in some places.
Usually, more precipitation falls in mountainous places than in flat areas. That’s because air can hold a lot of water. When wind blows wet air up a mountainside, the air gets colder. This temperature change often forces water to fall out of the air as rain or snow. In recent years, however, many mountainous areas across the world receive 25 percent less precipitation than normal.
