Looking up,I saw his eyes_____ on me in curiosity [ ]

________, more than 200 houses and buildings are heated by solar energy, not to mention the big cities

What have you learned from your experience in Japan? — Well, meeting people from another culture ___ be very difficult.

If you go by train， you can have quite ______comfortable journey， but make sure you take _____ fast one.

The new actor played the part quite____the old one.