1. $\text{This is the first time I have ever been to Sapa.}$
2. $\text{I have seen him since 2010.}$
4. $\text{The weather in sydney isn't as hot as in Rio de Janero.}$
5. $\text{They have lived to new york since 2004.}$
6. $\text{The last time we have been to Hanoi three year.}$
7. $\text{Big ben is the most famous in england.}$
8. $\text{New york is more modern than London.}$