TIL. Mark "True" or "False" :-1. In the mountain course, the river flows very slowly. 2. The south Indian rivers are rainfed rivers. 3. The smallriven that jom the main river are called tributaries. 4. Ox-bow lakes are formed in the middle course of a river.5. The source of river Ganga is the Zemu Glacier.IV. Answer in short:1. What is the catchment basin of a river? 2. Why do rivers flow slowly in the plain? 3. Give two favourableconditions for the formation of delta.4. Why is river ganga called ideal river? 5. What are distributaries?V. Define:1. Canyon 2. Potholes 3. Tributaries 4. Perennial rivers 5. WaterfallsVL Long answers :EX1. With the help of sketches, explain two features formed by the river in the plains.SET - III. Choose the correct option:1. The outermost layer of the earth's crust is made of a) water b) rock c) air2. Fossils are seen in a) igneous rocks b) sedimentary rocks C) metamorphic rocks3. Igneous rocks are called a) stratified rock b) unstratified rock c) metamorphosed rock4. In organically formed sedimentary rock is a) mudstone b) limestone c) diorite5. Petroleum reserves are found in a) sedimentary rocks b) igneous rocks c) metamorphic rocksII. Fill in the blanks:1. Igneous rocks formed at great depth are calledrocks. 3. Soil grains arein sandy soil.soil is ideal for idol making2. The sedimentary rocks are called4. When molten magma erupts, it forms55​