水平真空过滤机的真空滤盘是靠（）形成真空的
A.滤带传送装置
B.滤带再生装置
C.真空泵
D.自动排液装置
参考答案：C
用括号中的单词的适当形式填空。
1. _____ (be) you busy last night?
2. It's seven o'clock. The Smiths _____ (have) supper.
3. They _____ (have) a class meeting every week.
4. What _____ you _____ (do) last weekend?
5. Alice _____ (do) some reading on Sundays.
入赘后是否不再负担对父母的赡养义务？
