Only twenty percent of the work（）done yesterday.

单项选择题He tried many times to sneak across the border to a neighboring country,（）caught each time.

A. having been
B. only to be
C. always being
D. unfortunately

单项选择题All（）has already been done.

A. can be done
B. should be done
C. that can be clone
D. what should be done

单项选择题Neither he nor I（）from Canada. We are from Australia.

A. is
B. are
C. am
D. be

单项选择题It is chairman of the department ______ the teaching staff elected him.

单项选择题I prefer ______ there doing nothing.