橡胶塑炼的机理,可归纳为两个方面:一为(),一为氧化裂解。
参考答案:机械降解
After he retired from office,Rogers painting for a while,but soon lost interest.
A.took up
B.took off
C.took down
D.took in
能解决教育中无儿童、见物不见人倾向的课程观是()。
A.课程是知识
B.课程是计划
C.课程是经验
D.课程是活动