Which type of epithelial tissue allows transportation of substances through a selective permeable surface in the lining of food vessels or lung alveoli?
An insect walks 15 cm East, then it turns to its right and walks for another 20 cm. then it turns right and walks 4 cm, then it turns North and walks 20cm, then finally it turns to its left and walks 2cm. Where is the insect now with respect to its starting point.