Answer: D) Ichthyology Explanation: Ichthyology is the branch of biology devoted to the study of fish.   It is also known as Fish science which includes bony fishes (Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha).

Answer: C) 15 July Explanation: World Population day is an annual event, observed on July 11 every year, which seeks to raise awareness of global population issues.

Answer: D) P.S. Krishnan Explanation:

Answer: A) cruise Explanation: Cruise = a sea voyage for pleasure. All other words are related to ‘journey on land, sea with an aim’.

Answer: D) 2, 3, 1, 5, 4 Explanation: Firstly Rain falls and then Sun comes and Rainbow forms. After that Child sees the rainbow and feels Happy.

In Heights and Distances, The angle of elevation of an object is the angle between the horizontal and the line of sight that is the line from the object to the observer's eye.

Answer: A) 11.11% decrease Explanation: If earlier he is getting Rs. 1  per hr and working for 1 hr, income = Rs. 1Now he is getting Rs 1.3333 per hr and working for 0.66667 hrs Then income for 0.66667 hrs = Rs. 0.8889. If payment per hr is increased by 33.33 %  and working hours dereased by 33.33%, then 11.11 % decrease in income.

Answer: B) 115.395 sq cm Explanation: Because each vertice of the square is the center of a circle(1/4) part of the total area of each circle inside of the square.(3/4) part of the total area of each circle outside of the square.Thus total area outside the square is 434×227×3.5×3.5 = 115.3955 sq cm.