The respiratory systems of birds are very efficient at providing oxygen to the blood, which is necessary for birds to expend the energy necessary to fly. What feature of the bird respiratory system makes it more efficient than the respiratory systems of other animals?

A. a one-way air flow through the lungs and airways
B. a two-way air flow through the lungs and airways
C. bubble-like alveoli for gas exchange in the lungs
D. many tracheal tubes that connect the lungs to the skin

answer: tributaries flow into rivers.

wetland is a biome that develops when the water gets accumulated in a land exhibiting a huge depression. these form either seasonally or permanently. the water in the wetland comes from rivers, lakes, ocean, flood, rain or other sources. the wetlands includes mangroves, marshes and peatland.

tributaries flow into the rivers develops a wetland because such water will get deposited in the depression and will restrict the original flow of tributary water. hence, water with low drainage current combines with the river water.

the  different  of  these  two  are  that  they  differently  handle  their  team.

an  expressive  leader  focuses  on  the  task  at  hand  and  make  sures  that  their  goal  is  achieved.  they  accurately  finish  the  task.  an  instrumental  leader  on  the  other  hand  works  on  the  unity  of  the  group,  they  care  more  about  their  employees.  all  the  while  creating  a  good  environment.