Exercise 1.5.2.3: Look at the picture below and try to fill in the gaps without looking in the book.
The first letter of each word or short phrase is given

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In fall "t t" and blue flagging tapes are not clearly visible from a distance of 30 meters.



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During the dark times r t should be used in order to be visible.



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An effective G may be used for accurate marking of a r.