-_______do you spare time to visit your parents every month?-Twice.
As a rule, you can borrow only two books ______ in the library.
This kind of desk can be ______ to the height you need.
Mother was in the kitchen ______ lunch while I was ______ the coming exam.
—What do you admire the spaceman ______? —His bravery to travel around the earth ______ a spaceship all alone.
Are you ______ your son has difficulty in studying at school?