Is it possible for plant breeders to develop a true-breeding pink-flowered snapdragon?

No.

Explanation:

Pink flower colour in snapdragon is as a result of incomplete dominance. The pink flower colour has no allele in nature. Instead, the pink colour results from incomplete dominance of the allele that codes for red flower colour over the allele that codes for the white flower colour.

Assuming that the allele for red flower colour in the plant is R and the allele for white flower colour is r, true breeding red and white flower colour plants will have the genotype RR and rr respectively. In heterozygote state (Rr), the phenotype is usually pink, showing that the R allele has incomplete dominance over the r allele.

Hence, there is no way for plant breeders to develop a true-breeding pink-flowered snapdragon. without some genetic manipulations/mutation.

explanation:

b,bacteria convert nitrates

into nitrogen gas.

d,plants and animals take in

and use nitrogen compounds.

e,bacteria break down waste    

products and return nitrogen  

to the soil.

a,bacteria convert atmospheric

nitrogen to ammonia.

c,bacteria convert ammonia

to nitrites and nitrates.

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.