One of the requirements for the experiment is that the material to its burning temperature．
A. is heated
B. will be heated
C. be heated
D. would be heated
网友回答
A. is heated
B. will be heated
(答案→)C. be heated
D. would be heated
解析：考查虚拟语气：主语是requirements的时候，表语从句中用虚拟语气，sb （should） do，还有the material和heat是被动关系，用（should） be heated，句意：实验的一个要求是材料要被加热到沸点。选C。