Nancy took her temperature and found she had a .
A:cough
B:toothache
C:cold
D:fever
数学课上,老师讲了单项式与多项式相乘,放学后,小丽回到家拿出课堂笔记,认真地复习老师课上讲的内容,她突然发现一道题:﹣3x2(2x﹣+1)=﹣6x3+3x2y﹣3x2,那么空格中的一项是( )