Answer:
Option(D):Shirt...
Explanation:
As; Trouser,Socks and shoes are in pairs but shirt is not..
Insects, and some other invertebrates, exchange oxygen and carbon dioxide between their tissues and the air<span> by a system of </span>air<span>-filled </span>tubes<span> called tracheae. Tracheae open to the outside through small holes called spiracles. In the</span>grasshopper<span>, the first and third segments of the thorax have a spiracle on each side.</span>
