问题
单项选择题
机械密封的主要作用是将泄漏的轴向密封改为难泄漏的（）。
A.径向密封
B.填料密封
C.密封函
D.环向密封
答案
参考答案：A
搜题请搜索小程序“爱下问搜题”
机械密封的主要作用是将泄漏的轴向密封改为难泄漏的（）。
A.径向密封
B.填料密封
C.密封函
D.环向密封
参考答案：A
| 任务型阅读。 | |
| Dear Michael and Lisa, You're invited to a farewell(告别的)party for the " Liu family's visit to Australia. " The Liu family will leave on November 4th. The Liu family spent a happy week here with us. And they are going back to China directly(直接) after the visit. So we are giving the party on Sunday, November 2nd for Mr and Mrs Liu, and their son, Liu Tang and daughter, Liu Mei. Please go to Room 311 of Wonton Building. The party will start at 7pm and end at 10pm. There are drinks and food at the party. If you can come, please call at 528 - 090 and let us know before Friday, October 31st. Hope to see you there! 阅读材料，填入恰当内容完成邀请函。 | |
|