Please choose the correct ending to complete the given sentence: Sports and Fitness: [header] How to use a sextant [title] Know, if possible, your position above sea level. [step] If you're not using the sextant from aboard a ship at sea, you'll have to correct your sighting for your height above sea level. We'll discuss the correction later; for now, you just need to know your elevation above sea level.

Ending1: [title] Sight the horizon by looking through the horizon mirror. [step] The horizon mirror is only partially silvered, allowing you to look through it and through the sighting scope beyond it. Ending2: [title] Move your sextant to higher magnification than your actual height for the easiest and safest landing. [step] The additional magnification will provide you with more natural visibility. Ending3: [title] Know, however, that it will take longer to change sexes or sizes. [step] How long it takes you to change sexes from a fly-up to a mosquito is up to you, but it will help with the work. Ending4: [title] If landing on an open sea, raise your cv/bmp to 1000 mpg to face up. [step] To gain height following landing, don't lift up your cv/bmp, but lift up your fps or bmp.

Answer format: ending1/ending2/ending3/ending4