The phrase "which comprises both" is grammatically correct and can be used in written English.
It is often used to introduce a clause that clarifies or gives additional information about something previously mentioned. Example: "The new software has advanced features, which comprises both a user-friendly interface and powerful editing tools." This sentence means that the software includes both a user-friendly interface and powerful editing tools.
The congress named Andrews "natural family man of the year" for his advocation of the "natural" family, which comprises both a mother and father.
This week, parliament's joint human rights committee, which comprises both MPs and peers and is chaired by the former Labour deputy leader Harriet Harman, started to try to roll back the tide of uncertainty.
Goran Svilanovic, foreign minister of Yugoslavia (which comprises both Serbia and tiny, disaffected Montenegro), laments that the government has been unable to tackle reform because it has been "overwhelmed" by unexpected problems.
Post-functionalization of this polyoxometalate produces a drug delivery vehicle which comprises both kinds of inorganic and organic drugs.
His death has exposed the limitations of the slow-moving tribunal, which comprises both Cambodian and international judges, our correspondent adds.
Moreover, again in his terminology, natural sciences such as physics are but one branch of theoretical science, which comprises both empirical and non-empirical pursuits.
A number of African countries (Rwanda, Nigeria, Tanzania, Kenya and Ghana) are thus currently experimenting with various health insurance options which comprise both private and public schemes [10 14].
Keratinocyte cancers, which comprise both basal cell carcinomas (BCC) and squamous cell carcinoma (SCC), are cancers with high incidence but low mortality.
After measuring the Chl fluorescence characteristics, the same leaves were used for the measurement of chlorophyll content, which comprised both chlorophyll a and chlorophyll b.
The mixed delays, which comprise both discrete and distributed delays, are allowed to occur in a random manner governed by two mutually independent Bernoulli distributed random variables.
In detail, grit sizes of 80, 320 or 800 mesh, respectively, were applied in a one-step, dry grinding process which comprised both the removal of the topmost material layer and the surface finish.
