Answer: B) -2 Explanation: The sum of the oxidation numbers in a compound must equal zero. In the compound hydrogen sulfide, H2S, the two hydrogen atoms have an oxidation number of +1, for a total of +2. Therefore, the oxidation number of sulfur in the compound is -2, and the sum of the oxidation numbers is 0.

Answer: A) 28 Explanation: Let the original number is 82 i.e 8 + 2 = 10 and when the digits are reversed i.e 28The difference is 82 - 28 = 54 i.e, the number is decreased by 54.

Answer: C) Chalkboard Explanation: It is Blackboard or Chalkboard which is Black when clean, and as you write on it with white chalk it becomes dirty in White color.

Answer: B) 32 Explanation: Here the given series follows a pattern that, 22 - 0 = 4   32 - 1 = 8   42 - 2 = 14 52 - 3 = 22 62 - 4 = 32 Hence, the missing number is 32     Method 2 :: The difference between 4 and 8 is 4, the difference between 8 and 14 is 6, the difference between 14 and 22 is 8. So the next difference between 22 and the next number will be 10 since it follows (4,6,8,10 - add +2 each time) Hence, 22 + 10 = 32 is the missing number.

Answer: A) TRUE Explanation: Primary care physicians or General practitioners (GP) are the one you go first to get a check up, and if they deem that your problem more severe than they can help you, they will send you to a secondary care physicians like specialists in Cardiologists, Neurologists, Dentists, ...   Hence, the given statement, Primary care physicians are responsible for diagnosis and treatment is TRUE.

Answer: B) Flimsy Explanation: Durable means able to withstand wear, pressure.   Antonyms for Durable are Delicate, Flimsy, Short-lived.

Answer: D) DNA Replication Explanation: The First step of Bacterial Replication is DNA Replication. DNA must be copied in order to proceed.

Answer: A) The oldest generally accepted fossils of large animals range in age from 565 to 550 million years old. Explanation: The oldest generally accepted fossils of large animals range in age from 565 to 550 million years old.