Answer: B) Gradually Explanation: All of us, believe that the Solar System evolved from a giant cloud of dust and gas. They believe that this dust and gas began to collapse under the weight of its own gravity. As it did so, the matter contained within this could begin moving in a giant circle, much like the water in a drain moves around the center of the drain in a circle. At the center of this spinning cloud, a small star began to form. This star grew larger and larger as it collected more and more of the dust and gas that collapsed into it. Further away from the center of this mass where the star was forming, there were smaller clumps of dust and gas that were also collapsing. The star in the center eventually ignited forming our Sun, while the smaller clumps became the planets, minor planets, moons, comets, and asteroids.

ख‍रीफ फसलें – भारतीय उपमहाद्वीप में जून-जुलाई में बुआई की जाने वाली फसलों को खरीफ की फसलें कहा जाता है। इन फसलों की कटाई अक्टूबर और नवंबर में माह में होती है। इनको बोते समय अधिक तापमान एवं आर्द्रता तथा पकते समय शुष्क वातावरण की आवश्यकता होती है।

ख‍रीफ की मुख्य फसलें – कपास, मूंगफली, धान, बाजरा, मक्‍का, शकरकन्‍द, उर्द, मूंग, मोठ लोबिया (चंवला), ज्‍वार, अरहर, ढैंचा, गन्‍ना, सोयाबीन,भिण्डी, तिल, ग्‍वार, जूट, सनई आदि।