[35] I do not consider that it follows from the ability to give directions as to the way in which a sample is provided under section 48(4)(a) that the subsection requires actual involvement in the sample's provision. Moreover, the clear distinction in expression between subsections 4(a) and 4(b), the latter specifying who may take the sample while no equivalent provision is made in the former, provides a clear indication that the legislature did not intend the procedures to be identical. One can readily see why this should be so. The omission of urine and breath, in the course, respectively, of micturition and respiration are ordinary bodily functions. It is difficult to imagine how either could be extracted, with or without medical expertise. Blood, saliva and hair, on the other hand are all capable of physical removal, by force if necessary; and whether or not compulsion is involved, there is an obvious need for expertise in the process of removal, to avoid both physical harm to the subject and transmission of disease. There seems no warrant for reading into subsection 48(4)(a) a requirement for physical involvement of one of the specified persons holding medical expertise in the taking of samples, although it is perfectly logical that such a person or the general manager might, as provided by subsection (5), participate to the extent of giving directions.