27. The boy was busy doing his homework, only_____once in a while to look out of the window.
More highways have been built in China, ______ it much easier for people to travel from one place to another.
As he reached ______ front door, Jack saw ______ strange sight.
—Excuse me, I wonder if you can help me? — Sure. ______ ?
---Please sit down and have a break. You have been working for three hours. ---No, thank you. _____.
The new comers found it impossible to _____themselves to the climate to make permanent homes in the new countries.