How are spring and neap tides different from regular tides? 1. they occur twice a day. 2. they are caused by wind. 3. they occur twice a month. 4. they are extra-high tides and extra-low tides. 5. they are caused when the sun and the moon align and exert additional gravitational pull.

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.