Please help me ! I have question about visa B1/B2 Study incidental to visit

[Sheena0901]

Hi,
I have a question about my visitor visa to US.
I have Vietnam's passport.
My Passport's date of expiry is until 2020 .
This August i went to USA for a month for studying summer program course with my school. It was just a short course and we did visiting more than studying so I have a visa to US with theses information :
Type/ Class R B1/B2 ,
Entries M
Annotation : STUDY INCIDENTAL TO VISIT I-20 NOT REQUIRED. Then after my summer program finished, I came back to Japan.
But my Expiration Date in Visa is until July 2018.
Now my host family in US invites me to come to visit them again. So If I want to visit to US again in next February (before Expiration date), and i want to stay for 3 weeks, do I need to get a new visa or I can keep using this visa and just need to buy a flight ticket ? And is there anything else I have to do before I buy the ticket or when I first reach the counter in Airport in US , do they have any questions about my Visa ?
Thank you.

[jnk]

You can visit US on the same visa. You don't need to get new visa.

Notation: Study Incidental to Visit I-20 not required means your visa will be combination of some study and tourism. If you come to US for study you need to apply for student visa.

With this notation as per my understanding immigration officer at the port of entry most likely will not ask any further question.