21. When you cover the journal, you will have _______ better understanding of ______nature.
A. a; the B. the; a C. /; the D. a; /
22. ______ the climate changes so much has caused many discussions among the scientists.
A. What B. Which C. When D. That
23. The sports meet will be held on time ______ the bad weather.
A. because of B. regardless of C. instead of D. in favor of
