Which would be the major responsibility (责任，职责) of the chemical engineer？
A. direct research and development work
B. perform. chemical analysis (分析)
C. supervise (监督，指导) production work
D. direct other workers
【B20】
A. mistake
B. promise
C. answer
D. use
【B2】
A. sound
B. show
C. ten
D. seem
【B13】
A. fact
B. news
C. demand
D. order
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