__ is really hard __ them to climb Mount Tai.
---That’s a nice mobile phone. ---It is. My aunt _____ it for my last birthday.
---What does Tom’s uncle do? ---He is a teacher. He __________ physics at a school now.
She has many nice dresses. She wears a different one every day ______ the week.
—I am leaving for Switzerland next week.— !
— I called you yesterday evening, but nobody answered the phone.— Oh, I a walk with my parents at that time.