用所给词的适当形式填空。 1.  The boys in my class are ______(cautious) not to make any mistakes in spelling than ever before. 2.  I am ________(negative) that you took down my number incorrectly. 3.  He has a real ________(enthusiastic) for teaching. 4.  She noticed a sudden _______(move)  behind the tree. 5.  They discussed the situation _________(private) . 6.  Scientists disagree about how the universe________(creative). 7. Such problems are a______(universe) feature of all ages. 8.  I suddenly lost my balance and fell _______(forward) .