某建筑材料采购合同中，约定由需方负责提货，则交货日期应是()。A.以需方收货戳记的日

计算（-3a³）•（-2a²）=______．

已知3a^y+4b^3x-1与-3a^2x-2b^1-2y是同类项，则x=______，y=______．

用所给动词的适当形式填空。

1. Look! The girls ______ (write) on the wall.

2. Would you like something ______ (eat)?

3. Don't ______ (stand) behind the wall!

4. I want ______ (take) some books to the classroom.

5. Lucy is running. Lily ______ (not run).

6. There ______ (be) a football and two flowers on the table.

7. Let the boy______ (watch) TV.

8. What can you ______ (see) in the picture?

9.  ______ the old woman ______ (drink) tea now?

10. You must ______ (look) after your things.

人体处于何种体位时，外半规管与地面垂直（）

A.直立位

B.平卧位

C.直立位头前倾30°

D.平卧时头前倾30°

E.直立位头后仰30°

周的始祖名叫“( )”，他善于经营农业，号曰“后稷”，尧时任农师。

A．公刘

B．姬发

C．弃

D．契