Answer: A) Solid carbon dioxide Explanation:   Dry ice is solid form of carbon dioxide, used as a cooling agent.   It lower temperature than that of water ice and not leave any residue.

Answer: A) 541 times Explanation: There are 60 minutes in an hour. In ¾ of an hour there are (60 × ¾) minutes = 45 minutes. In ¾ of an hour there are (60 × 45) seconds = 2700 seconds. Siren sounds for every 5 seconds. In 2700 seconds = 2700/5 = 540 times. The count start after the first sound, the Siren will sound 541 times in ¾ of an hour.

Answer: B) 5 Explanation: A regular Pentagon have 5 sides and 5 lines of symmetry.  The number of lines of symmetry in a regular polygon is equal to the number of sides.

Answer: B) 338 Explanation: We know that 40% = 25   40% of 265 + 35% of 180 = 50% ?   25 x 265 + 35% of 180 = 50% ?   We know that (35% of 180 = 180% of 35) & 180% = 95   25 x 265 + 95 x 35 = 50% ?   106 + 63 = 50% ?   ?= 2 x 169 = 338.

Answer: D) haemoglobin Explanation: Oxygen in our blood is transported by a protein named Haemoglobin.

Answer: C) Vacuum Explanation: Sound waves cannot travel through a Vacuum.   A vacuum is an area without any air, like space. So sound cannot travel through space because there is no matter for the vibrations to work in.

Answer: D) 215 degrees Explanation: The total angle traced by the hour hand is the angle traced in 7 hours and 10 minutes.We know that the angle traced by the hour hand in one hour is 30º and in one minute is 1/2º.Therefore, (30º x 7) + (10 x 1/2º) = 215º is the angle traced by the hour hand.

Palm tree.