People always be careful with fire or it can be dangerous.A. canB. needn’tC. mustD. shoul

问题补充：

People always be careful with fire， or it can be dangerous.

A. can

B. needn’t

C. must

D. shouldn’t

答案：

A. can

B. needn’t

(答案→)C. must

D. shouldn’t

解析：本题考查四个情态动词的含义，根据语境可知选择C表示必须之意。句意：人们必须一直对火小心，否则它可能很危险。