1:
2? - в тексте написано, что языку обучаются с ранних лет, а в варианте "до 5 лет), так что спорно.
4, 5
2:
operation, untrue, hateful, speechless, foreigner, meeting, bravely.
3:
swum
read
become
borrowed
rung
done
been
4:
drugstore
cookie
sweater
gas/gasoline
faucet
garbage
student
5:
is
for
-
to
into
vocabulary
even
6:
I have never been to North America.
Have you seen Nelson's Column yet?
Has Jenny ever used a bilingual dictionary?
We have just learned some international words.
Jason has already met some people form Australia.