The writer then clearly shows they are moving on to the other argument which is their own (and it has clearly been stated in the thesis that this is their argument): In this paragraph, 'they' is dropped because it is now the writers opinion
Not everyone wants to buy tobacco only to do nothing with it for years. According to Patel, if his tobacco has not undergone enough fermentation, hell be able to detect the actual fertilizer used in the fields once he smokes it
Consistent with the notion that structural alterations in these regions are a product of prolonged nicotine/tobacco exposure, group differences between smokers and nonsmokers within, for example, the insula were not detected among an adolescent/young adult participant sample with relatively lower exposure levels (0.9 0.7 pack-years on average) [85] but were observed among similarly aged individuals with relatively higher exposure levels (4.0 1.8 pack-years) [86]
SIZES In Spain, the size that was developed based on consumer preference was approximately 78mm long by 44mm high
Moreover, PY-dependent increase in cardiovascular risk among smokers was amplified in those with lower ages at initiation, and earlier smoking initiation under age 30 was associated with progressively higher cardiovascular risks and all-cause mortality