The phrase "are mostly very low" is correct and usable in written English.
It can be used to describe a situation or condition where the majority of something is at a low level or value.
Example: "The temperatures in this region are mostly very low during the winter months."
Alternatives: "tend to be quite low" or "are generally quite low".
The sacbes are mostly very low, reaching a maximum height of about only 2 m between Groups C and D. North of Structure C-l, the top half of a figure was found, carved almost in the round, but it was extremely eroded and was not photographed.
However, individual serotype prevalences are mostly very low, so fixed or random effects models were deemed impractical.
The reason is that the interfaces of protein-ligand interactions are small and most interfacial residues are exposed in the solvent to a certain degree; thus the burial levels of the atoms are mostly very low and imply little information.
Cook's distance values were mostly very low (median 0.03 0.04), indicating few points with undue influence.
Use of antibiotic prophylaxis for caesarean section in a single does administered after clamping of the umbilical cord was mostly very low or non-existent across all the hospitals.
Furthermore, the allele frequencies of CNVs in both populations were mostly very low.
They analysed and reported results for physical and psychosocial hazards separately and did not discuss their comparative influence on risk, but it is noteworthy that hazard ratios (HRs) for physical hazard exposures were mostly very low and few were statistically significant, whereas many of the HRs for psychosocial hazards were high and most were significant.
In part, Hispanics tend to stay away from the polls because many adults are non-citizens, and those who are eligible to vote are mostly very young and have low incomes.
Facebook is a frothing pot of insanity and reactionary outrage, but it's mostly very repetitive and relies on increasingly low-res memes bandied about by retirees whose brains are turning into cottage cheese and seeping out of their ears.
