पर्वतीय क्षेत्रों में बहते समय एक नदी जलप्रपात (waterfalls) बनाती है। जलप्रपात बनने के दो मुख्य कारणों का चयन करें: (a) नदी पेड़ों के बीच से गुजरती है। (b) नदी बहुत कठोर चट्टानों के ऊपर से बहती है। (c) नदी नरम चट्टानों के ऊपर से गुजरती है। (d) नदी एक तीव्र ढाल वाली घाटी से नीचे गिरती है।

The crescent-shaped sand dunes found in Sam, Jaisalmer are scientifically known as:

With reference to fjords, consider the following statements: I. They are deep, narrow inlets carved mainly by glaciers and later occupied by seawater. II. The shallow sill near their mouth is generally associated with glacial deposition rather than with tectonic uplift alone. III. They are chiefly associated with high-latitude or formerly glaciated coasts, rather than with humid tropical landscapes. How many of the statements given above are correct?