Oxygen is highly reactive and is a critical chemical component necessary to sustain the process of combustion (burning).
37. Muscles of the heart are called ……………………………… muscles.
(A) Cardiac
(B) Voluntary
(C) Involuntary
(D) None of these
Answer:
(A) Cardiac
Explanation:
The heart is made of specialized involuntary muscle tissue medically referred to as cardiac muscle, which continuously pumps blood without conscious effort.
38. In which year Dandi March took place?
(A) 1940
(B) 1930
(C) 1925
(D) 1932
Answer:
(B) 1930
Explanation:
The Dandi March, an act of nonviolent civil disobedience led by Mahatma Gandhi against the British salt monopoly, took place in March and April of 1930.
39. The system that supplies blood to all part of the body is:
(A) Respiratory system
(B) Circulatory system
(C) Excretory system
(D) Nervous system
Answer:
(B) Circulatory system
Explanation:
The circulatory system, consisting of the heart, blood vessels, and blood, is responsible for transporting oxygen, nutrients, and hormones to cells throughout the body.
40. Three percent of all the worlds water is:
(A) Salt water
(B) Unreachable
(C) Ice
(D) Fresh water
Answer:
(D) Fresh water
Explanation:
While oceans cover most of the globe, 97% of Earth’s water is salt water. Only about 3% of the world’s water is fresh water (found in glaciers, groundwater, and lakes).
