This exercise is very difficult. I can't do ____.
This exercise is very difficult. I can't do it.
They can't speak English very well. Can you help ____?
They can't speak English very well. Can you help them?
It's a great song. I love ____!
It's a great song. I love it!
My dad works in Ho Chi Minh city. I don't see ____ very often.
My dad works in Ho Chi Minh city. I don't see him very often.
Ms. Kate is calling you! Can you talk to ____?
Ms. Kate is calling you! Can you talk to her?
Hiro and Nora are really nice. I like ____.
Hiro and Nora are really nice. I like them.