for ten years or so
10年間かそこら
for the benefit of humanity
人類の利益のために
for the express purpose of doing
特に…する目的で
for the first [second, last] time
初めて[2度目で,最後に]
for the first time in many years
何年かぶりに
for the first time in one's life
人生初めて
for the foreseeable future
ここ当分の間は
for [in] the foreseeable future
当面は
for the good of mankind
人類のために
for the last few decades
ここ2,30年の間