The phrase "demonstrates a combination of" is correct and usable in written English.
It can be used when describing how different elements or qualities come together to create a particular effect or result.
Example: "The research paper demonstrates a combination of innovative techniques and thorough analysis."
Alternatives: "shows a blend of" or "exhibits a mix of".
A side-room with a window demonstrates a combination of natural and artificial lighting during the day (f).
This method demonstrates a combination of off-the-shelf inkjet printing and biomaterials and has potential to be adapted to tissue engineering and colony patterning applications.
Examples of design deficiencies are presented; partitioned into in-plane (notched shear web) and delamination (stiffener runout) to demonstrate the respective failure modes, whilst the third case study (generic nacelle element) demonstrates a combination of these modes.
As this year's MetLife survey demonstrates, a combination of policy pressures and budget cuts has made teaching harder and less attractive than any time in recent decades.
Awarded annually to "a living architect whose built work demonstrates a combination of those qualities of talent, vision and commitment, which has produced consistent and significant contributions to humanity and the built environment through the art of architecture," last week, the committee revealed their winner for this year.
These masks demonstrate a combination of realistic, imaginative, and supernatural qualities that is uniquely Eskimo.
At the time, General Musharraf demonstrated a combination of boldness and agility that enabled him to prevail in the face of extraordinary pressures.
The excerpts from Mr. Fineman's fictional exploitation film demonstrate a combination of cheesiness and ineptitude heretofore unseen in an American movie.
As his biographer Lou Cannon put it, "Reagan had climbed the ladder of success from the lower rungs, demonstrating a combination of persistence and humility rare among either politicians or actors".
Justice Souter issued a dissent saying that officials in Alaska had "demonstrated a combination of inattentiveness and intransigence" that add up to "procedural unfairness that violates the due process clause".
It's hard to imagine that anyone could make you feel sorry for Abu Zubaydah, but his C.I.A. interrogators demonstrated a combination of brutality and incompetence that actually manages to achieve this.
