塑性流体流动可经过（）流态。
A、4种
B、5种
C、3种
D、6种
参考答案：B
根据课本Unit 8《Celebrating Me》的内容回答下列问题。
1. Who does Li Ming ask for help?
__________________________________
2. Does Li Ming know what to write about himself?
3. Can Jenny help Li Ming?
4. Can Jenny write the report for Li Ming?
GPRS detach的发起方可以是（）。
A.MS
B.SGSN
C.PDN
D.HLR
