21. ---What attracts people to California is its pleasant climate and relaxed lifestyle.
---This is ____ each year a great number of people from all over the world try to ____ to California.
A. how; immigrate B. Why; immigrate C. because; remove D. why; remove
22. You can easily find the line, which is _______ with an arrow.
A. noted B. made C. signed D. marked
