We are going to have a dinner party next Saturday
-We will have a dinner party next Saturday. 
''Why don't you take a photo?''Tim asked Ann
Tim asked Ann to take a photo
Lan started learning music 2 years ago
-Lan has learnt music for 2 years
Lan:''Modern technology save us lots of time''
Chau:''..."
a. I thnk it's all right      b. OK.That's all
c. I can't agree with you more
d. Not at all
Mr.Minh:''Did the aliens see you?''
Nick:''....When i saw them,i hid behind a big tree''
a. Yes they are    b. No the don't     C. i don't know     d. all are
We/not/know/how many/solar systems/there/be/each galaxy
We don't know how many solar systems there is in each galaxy.
there/be/many explorations/Mars/by humans/since the mid 20 century
There has been had many explorations Mars by humans since the mid 20 century.