43. Pick up the correct statement from the following:
A. The operation of removing material from the sea or river bed is known as
B. Dredging
C. Digging
D. None of these.

---

44. If h and hi are the heights of a light house and the observer in a ship in metres above M S L then the horizontal distance from the ship to the light house in kilometres is
A. 3.86 (.^ITi1-NriT)
B. 3.86 (ih. - hi)
C. 3.86 (X x 111,1)
D. 3.86 TE NFL ? hi).

---

45. Pick up the correct statement from the following :
A. An artificial barrier which makes the enclosed area safe for anchorage of ships, is known as break water
B. The break water whose inside is used as a plateform for loading and unloading is called a mole
C. The length of the quay wall is governed by the length of the largest vessel likely to be berthed
D. All the above.

---

46. Pick up the correct statement from the following :
A. For nautical purposes, low water level is generally referred to by the navigators
B. The depth of the bed of the sea from the surface of water is called sounding
C. The contour lines on the bed of a water body are called fathoms
D. All the above.

---

47. Which one of the following land marks on the coast line must be depicted on hydrographic maps ?
A. shore line
B. light houses
C. church spires
D. all the above.

---

48. Which one of the following statements is correct ?
A. The soundings are made with respect to the mean low water
B. The soundings which are below the datum are written in black on the map
C. The spot heights of the features above datum are written in red on the map
D. All the above.

---

49. The heaviest line is used to democrate
A. the low water line
B. the high water line
C. the limit of swamps
D. the direction of current.

---