MEDICAL RESEARCH AT THE CELLULAR LEVEL, _______ RESEARCH ON THE IMMUNE SYSTEM, HAS BEEN MADE POSSIBLE THROUGH TWENTIETH-CENTURY ADVANCES IN TECHNIQUES OF GENETIC RESEARCH

25. - DE THI THU NXB BO GD CO DAP AN
DE THI THU NXB BO GD CO DAP AN
25. Medical research at the cellular level, _______ research on the immune system, has been made possible through twentieth-century advances in techniques of genetic research. A. which B. Whereas C. such as D. is also