Answer: Option D. -> Africa
Answer: (d)

Answer: Option D. -> Taiga forest of Siberia
Answer: (d)Taiga is the world’s largest land biome. It makes up 29% of the world’s forest cover. Also known as boreal forest or snow forest, it is characterized by coniferous forests consisting mostly of pines, spruces and larches. The largest areas of Taiga are located in Russia and Canada.

Answer: Option C. -> not easily worn down
Answer: (c)
Granite is high in quartz, a mineral very resistant to weathering. Similarly, quartzite is harder than steel. So, they are not easily worn down and give rise to upstanding mountains and hills (Environmental Biology by P.D. Sharma, p. 37).
However, they are subject to differential weathering: a rock that is resistant in a climate dominated by chemical weathering may be weak where the physical weathering process dominates, and vice versa. So quartzite, though hard and chemically inert, can be fractured by physical weathering.
Similarly, granite outcrops in arid or semi-arid region resist weathering; however, the minerals in granite are susceptible to alteration by oxidation, hydration and hydrolysis, particularly in regions with warm, humid conditions (Essentials of Physical Geography by Robert Gabler, James Petersen, L. Trapasso, p. 34).

Answer: Option D. -> Crust and upper mantle
Answer: (d)Lithosphere consists of crust and upper mantle.

Answer: Option D. -> Trellis
Answer: (d)When a river is joined by its tributaries at almost right angles, it develops a trellis pattern. Trellis pattern develops where hard and soft rocks exist parallel to each other.

Answer: Option A. -> Valley deepening
Answer: (a)
The youthful stage of the river is when water flow is the quickest. Because of a steep slope and steep channel gradient in this stage, rivers actively deepen their valleys through vertical erosion.
The valley becomes deep and narrow characterized by steep valley side slopes of the convex plan. Waterfalls, V-shaped valleys and interlocking spurs are features of this stage.

Answer: Option B. -> Africa
Answer: (b)

Answer: Option B. -> the equator from south to north
Answer: (b)
A traveller crossing the International Date Line eastbound subtracts one day, or 24 hours so that the calendar date to the west of the line is repeated. Crossing the IDL westbound results in 24 hours being added, advancing the calendar date by one day.
The International Date Line is necessary to have a fixed, albeit arbitrary, boundary on the globe where the calendar date advances in the westbound direction.

Answer: Option D. -> Germany
Answer: (d)

Answer: Option C. -> United State of America (USA)
Answer: (c)