In which trophic level does the Sparrow belong as a consumer?

Given below is a simplified model of phosphorus cycling in a terrestrial ecosystem with four blanks $(A-D)$. Identify the blanks.

The following chart shows the phosphorus cycle in a terrestrial ecosystem. Select the correct option for the four labels $a, b, c$ and $d$ shown in the diagram.
$a$ - $b$ - $c$ - $d$

Match Column-$I$ with Column-$II$. Select the option with the correct combination.

$1$. Standing state	$p$. Mass of living material at a given time
$2$. Pioneer species	$q$. Amount of nutrients in the soil at a given time
$3$. Detritivores	$r$. Species that invade a bare area
$4$. Standing crop	$s$. Breakdown detritus into smaller particles

The bulk fixation of carbon through photosynthesis takes place in

The energy obtained from fossil fuels is essentially a product of which of the following?