如果a<0，那么a和它的相反数的差的绝对值等于[ ]
A.a
B.0
C.-a
D.-2a
答案：D
解释句中加点字的意思。（4分）
①卒用其人：___________ ② 如探汤： ___________
③ 卧房槛外： ___________ ④ 非显者刺：___________
It's ____ wise choice to use a four wheel drive car on ____ snowy day.[ ]
A. a; a
B. the; /
C. /; a
D. the; the
to use a four wheel drive car on ____ snowy day.[ ]