We are always ready ______ others. [ ]
A. to helping
B. to help
C. help
D. helping
答案:B
将函数y=x2+x的图象向右平移a(a>0)个单位,得到函数y=x2﹣3x+2的图象,则a的值为[ ]
A.1
B.2
C.3
D.4
“别日何易会日难”出自曹丕的《燕歌行》,李商隐曾经化用了这句诗写下了哪句千古名句?