use activity diagram to model a system

  Only a flavouring.

  I found to use activity diagram to build a system model is a good choice for me.Instead of modeling with sequence diagram,I model another model of filesharing with activity diagram.

  Now I have finished the analysis model,base on this,I will make a design model in my spare time.

NCE L19:can,could,may,might

1.request permission;

polite:can(friends and equals)<could,may<might(superior)

2.may/might + infinitive

  may/might + perfect infinitive

3.may/might as well + infinitive

  for example:

  I might as well play game( as learn english-it makes no difference).

"have" and "have got"-L18

  When "have" expresses the meaning of "possess",it equal to "have got".

  For example:

  This sock has (got) a hole in it.

  This room has (got) four windows.

  But in the sentence below,it cann't be replaced by "have got":

  They had a good time at the party.

  its meaning is:to enjoy or suffer;experence,often as part of a group

  At this viewpoint,"have" is a unversal word.for example:have meal,have letter,have a look,have it...

  We can view these in LONGMAN dictionary.p701-702

NCE L17:"must" versus "have (got) to"

  There are two way in "must".

  First,it says:this is your necessity,you have to face this meaning,it has no PAST tense and FUTURE tense itself.

  PAST TENSE:I had to do it.

  FUTURE TENSE:I will have to do it.

  Second,it says:this is your obligation.This is a this meaning,it can express a past action: (modal + perfect inifitive) He must have done it.

  Another point:

  I have to do it.(no contraction)

  I've got to do it.(the contraction is always used)

return the work

  Three weeks before,I applied for an Open Source Software Engineering Project at has not been approved.I think,I can learn something from this.

  I plan to do a design with UML for the filesharing module.

  I think that giving up all other learning except my main aim absolutely is not very proper-like flavouring versus food.