?theory?and?secondary?schools?have,?but?how?to?apply?in?practice,?most?of?the?students?did?not?pass?the?hard?work?is?not?a?short?time.21?camera?high?school?trigonometric?function?students?soon?can?understand?the?principle?of?artillery?fire,?but?only?primary?school?culture?of?Ding?Yonggang,?to?understand?the?need?to?master?this?technology,?a?lot?of?difficulty:?\"we?are?equivalent?to?the?distance?between?the?eyes?of?adjacent?edges?and?adjacent?edges?more?angle?is?big,?small?angle?error?will,?training?is?the?most?basic?angle?of?observation?and?calculation.\"shot?22?he?never?went?to?high?school?classroom?learning,?not?in?trigonometric?function,?but?he?speaks?up,?like?many?years?engaged?in?education.lens?23?Ding?Yonggang?with?a?pass?and?a?pen,?softly?to?the?students?said:?\"the?general?calculation?method?of?coordinate?is?operation,?coordinate?inverse?calculation,?intersection,?the?rear.?Trigonometric?functions?in?sine,?cosine,?tangent?and?cotangent,?secant?cosecant?should?be?used.\"lens?24?is?a?team?of?students?trooped?into?the?park,?Ding?Yonggang?had?to?wait?there.lens?25?Ding?Yonggang?stood?in?the?door?of?85?cannons,?the?students?stood?listening:?\"our?artillery?mirror?and?above?the?steering?wheel?is?a?pass,?and?gun?sight?not?only?above?the?pass,?gun?is?a?piece?of?steel,?no?way.?The?firing?of?guns?is?dependent?on?the?Scout's?steering?wheel.\"lens?26?each?training?is?ing.?A?graduation?examination?must?be?carried?out?with?a?certificate?of?pletion.shot?Ding?Yonggang?in?the?selected?27?lesson?examination?questions,?the?examination?questions?submitted?to?the?captain's?hands,?he?questions?of?unity.28?lens?on?the?students?a?test?is?necessary.?He?told?them?to?pay?attention?to?the?examination,?but?more?attention?should?be?paid?to?the?training?subject?of?understanding?and?use,?to?learn?to?master?the?operation?precision?and?speed,?let?their?shells?send?accurate?drive.lens?29?whenever?the?end?of?the?training,?each?student?teacher?to?identify,?for?outstanding?students,?the?training?team?to?remend?to?the?original?unit,?the?troops?always?maintain?excellent?technical?strength.shot?30??participants?on?each?evaluation???identification,?he?would?write?to?me?personally,?and?see,?the?advantages?and?disadvantages?of?short?term?and?let?them?know?that?do.