解方程（1）3x-2=2x+3（2）4-x3=x-35-1．

已知集合A，B，则A∪B＝A是A∩B＝B的(　　)

A．充分不必要条件

B．必要不充分条件

C．充要条件

D．既不充分也不必要条件

Mike works very long hours every day. He usually gets up at 17:00. He has a shower and makes his breakfast. What a funny time to make breakfast! After breakfast he practices his guitar. Then he puts on his jacket and goes to work. To get to work, he takes the number 17 bus to the Star Hotel. The bus usually leaves at 19:15. He works all night. People love to listen to him! He gets home at 7:00, and he watches the early morning news on TV. He goes to bed at 8:30, a tired but happy man. Can you think what his job is?

小题1:How long does Mike work?

A．7 hours

B．8 hours

C．about 9 hours

D．all night小题2:He ____________ and makes his breakfast.

A．gets up

B．takes a shower

C．works

D．washes his face小题3:What does Mike do after breakfast?

A．He goes to work.

B．He puts on his clothes.

C．He practices his guitar, then puts on his jacket and goes to work.

D．He practices his guitar.小题4:Maybe（可能）he is ________________________.

A．a worker

B．a singer

C．a writer

D．a teacher小题5:How does he go to work?

A．By car

B．By bikes

C．On foot

D．By bus

切削加工性与材料的（）等有关。

Ⅰ．种类；Ⅱ．成分；Ⅲ．硬度；Ⅳ．塑性；Ⅴ．组织。

A．Ⅰ+Ⅱ+Ⅲ+Ⅳ＋Ⅴ

B．Ⅰ+Ⅲ+Ⅳ

C．Ⅰ+Ⅲ++Ⅳ+Ⅴ

D．Ⅰ+Ⅱ+Ⅲ+Ⅳ

某多层住宅端下条形基础，其埋置深度为1000mm，宽度为1500mm，砖墙厚240mm，钢筋混凝土地梁宽度为300mm，地基各土层的有关物理特性指标、地基承载力特征值f_ak及地下水位等见图所示。

试问，淤泥土层顶面处经深度修正后的地基承载力特征值f_az（kPa），与下列何项数值最为接近（）。

A．66.73

B．69.23

C．80.18

D．87.68

在SQL的SELECT语句中，用于实现选择运算的是（　）。

A．FOR

B．WHILE

C．IF

D．WHERE