垫片按照材料和结构可以分为()。
A、金属包垫
B、非金属垫片
C、金属复合垫片
D、金属垫片
参考答案:B, C, D
Which of the following underlined parts is different in pronunciation from others?
A.Don’t pick flowers in the park.
B.He is waiting downstairs for you.
C.Do you know how to solve the problem?
D.What do you want to be when you grow up?
国有企业领导人员应当切实维护()利益,不得有()的行为。