Дополните предложения, обращая внимание на форму времени
глагола-сказуемого главного и придаточного предложений.
1. My friend hasn't come to see me since... 2. His sister
has learnt three foreign languages since... 3. I haven't
been to the Crimea since... 4. I've known Smirnov since...
5. Have you been to the Caucasus since...?
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