甲数减乙数的差是0.82，如果将乙数增加0.18，那么这时的差应是（ ）。
0.64
My father _____ gave me some exercises and told me to do them _____. [ ]
A. myself, by myself
B. himself, by myself
C. herself, by herself
D. yourself, by yourself
定金的数额由当事人约定，但不得超过主合同标的额的20%。( )
