Plant species differ in that renewed growth in spring can be triggered by day length or by temperature or else by a combination of both  Day length is the same, year after year, for any given date
Ttherefore, any plant species that starts to grow again on widely different dates in different years resumes growth at least in part in response to temperature
In Xandia, medical assistant trainees must either complete a formal training course or work for one year under the close supervision of a physician. Since few physicians are willing to act as supervisors, it must be true that most medical assistant trainees in Xandia take the training course.