1 Hanh eats too many sweets, so he has toothache.
Because Hanh  eats too many sweets, he has toothache.
2. Both Tuan and her brother are interested in learning English.
Tuan is interested in learning English, and so does her brother
3. She began donating books and clothes ten months ago.
she have donated books and clothes for ten months .
4. This exercise is more difficult than that one.
That exercise isn't as difficult as This exercise
5. He sells tickets at the gate of the tourist site.
Tickets are sold at the gate of the tourist site.