Directions: Read the following information and answer the questions given below it:
A is the father of C. But C is not his son.
E is the daughter of C. F is the spouse of A.
B is the brother of C. D is the son of B.
G is the spouse of B. H is the father of G. 

Who is the grandmother of D?   

Read the passage carefully and give the answer of following questions.
One of the American Navy's greatest losses during World War if was inflicted not by the Japanese, but by the weather. On the evening of 17 December 1944, destroyers, cruisers and aircraft carriers of the Third Fleet Task Force 38 were replenishing stocks of food, fuel and ammunition during a sea rendezvous with support ships when a savage tornado struck the Philippine Sea. One of the commanders said later: 'My ship was riding as though caught in some giant washing machine. We were rolling between heaving clifs of water, caught in so strong a vice of wind and sea that our 50,000 horse- power engines were helpless. It was nine hours before he regained control of his ship, after the fleet had bobbed like helpless shuttlecocks, unable to prevent collisions in the sledge hammer waves.

The ships caught in the tornado 

capacitor is a of small size but high capacity?

An observer on the top of a mountain, 500 m above the sea level, observes the angles of depression of the two boats in his same place vision to be 45 ° and 30 ° respectively. Then the distance between the boats, if the boats are on the same side of the mountain, is