Rewrite the following by using the Present Perfect Tense.
e.g. she / receive three letters since the beginning of the week.
She has received three letters since the beginning of the week.
1. they / already practise for five hours
2. we / study since this afternoon
3. I / just finish my work
4. David / never learn Japanese
5. she / recently return from China
6. you / not work hard enough
7. I / not go to the library yet
7 tane var aklımda