Answer:
The correct answer is option D.
Explanation:
From the given options the reaction which is not a double replacement reaction is:

This because the above reaction is an example of single replacement reaction.

Whereas;
Double replacement reaction is a type of chemical reaction in which exchange of ions among the reactants take place.

Answer:
A Chinese Geomancer
Explanation:
The compass was invented in China during the Han Dynasty between the 2nd century BC and 1st century AD where it was called the "south-governor" or "South Pointing Fish" (sīnán 司南). The magnetic compass was not, at first, used for navigation, but for geomancy and fortune-telling by the Chinese.
However, it is believed Flavio Gioia first invented the refined compass, and a monument has been erected in Almafi Italy to honor his invention. The magnetic compass was probably developed by combining the wind rose and the lodestone. From this device it is supposed the compass rose evolved.
I would say D) two high tides and two low tides each day
Given that,
Distance, d = 10700 km
Time taken by the airplane to complete the destination, t = 12 hours
We need to find the speed of the airplane. It is equal to the total distance covered divided by total time taken. So,

We know that,
1 km = 1000 m
1 h = 3600 s
So,

So, the speed of the airplane is 891.66 km/h or 247.68 m/s.