Question 10 and are mountainous plants Question 17 and float on the surface of water Question 18 The changes in our environment are called Question 19 do not have streamlined body Question 20 During hibernation, certain desert animals hide themselves in burrow with secretions and sleep for 8 to 4 months

Question 10andare mountainous plants? Ans :- Alpine plants are plants that grow in an alpine climate, which occurs at high elevation and above the tree line. ... These include perennial GRASSES, sedges, forbs, CUSHION plants, mosses, and lichens.Question 17andfloat on the surface of water? Ans :- Due to the surface tension, SMALL objects will "float" on the surface of a fluid, as long as the object cannot break through and separate the top layer of water molecules. When an object is on the surface of the fluid, the surface under tension will behave like an elastic membrane.Question 19do not have streamlined body ? Ans :- The two sea animals do not have streamlined and bilaterally symmetrical body are starfish and octopus.Question 20 During hibernation, certain desert animals hide themselves in burrow withsecretions and sleep for 8 to 4 months ? Ans :- Such animals are called nocturnal. Certain animals hide themselves in burrows with gelatinous secretion and sleep for about 8 to 9 months in a year. This is called aestivation or summer sleep.