"thoroughly demonstrate" is correct and usable in written English.
You can use it to say that someone has shown something in great detail and/or with a comprehensive amount of evidence. For example: "The professor's lesson thoroughly demonstrated the principles of quantum mechanics."
The case study of the change pathway of the stabilized inverted pendulum is provided to thoroughly demonstrate the applicability of the suggested theory.
Furthermore, coronary angiography can only provide a two-dimensional outline of the coronary lumen and cannot thoroughly demonstrate the complex nature of atherosclerotic plaques which are responsible for association between the angiographic findings and clinical outcome [ 1].
Third, the number of laboratory-confirmed RV infections was not sufficient to thoroughly demonstrate the cross-protection against RV gastroenteritis caused by serotypes G1 and G9, which are the most common serotypes, and serotype G3 in China.
"This thoroughly demonstrates the lack of credibility" of Mr. Thacher's report, Mr. Stancik said.
The panel believes the effec tiveness of cloud seeding has been thoroughly demonstrated.
It will also be thoroughly demonstrated in lab during check out session.
Will Senate Republicans finally check the career of a president, and a party, that has so thoroughly demonstrated its depravity?
The success of this process thoroughly demonstrates the methodological possibility of gene knockout through homologous recombination in Thermoanaerobacterium.
Perhaps the ultimate validation of appropriation art, it thoroughly demonstrates how existing works of art — in this case films — become raw material for new ones.
That it didn't work out there is hardly surprising, since no book (except, perhaps, "The Silent Woman," Malcolm's earlier book about Sylvia Plath and Ted Hughes) has so thoroughly demonstrated the uselessness of biography.
The robustness of this controller is thoroughly demonstrated in the above hybrid power systems with different conditions of load disturbances, wind power and parameter variations.
