c. has been
Answer: c. has been
6. Did you know he's been teaching German _____ fifteen years?
Baca Juga: Rumus, Fungsi, dan Struktur Present Perfect Tense dalam Kalimat
a. before
b. since
c. for
Answer: c. for
7. We have been watching TV _____ we had dinner.
a. for
b. since
c. by