已知1<x<3,化简|x-3|+|x-1|等于( )
A.2x
B.-2
C.2
D.-2x
∵1<x<3,
∴x-3<0,x-1>0,
则原式=3-x+x-1=2.
故选C.
— I am worried I can't get into a good high school because I'm weak ______ English.
— Don't worry. ______ and asking a teacher for help can help a lot. [ ]
A. in; Work hard
B. in; Working hard
C. at; Working hard
D. at; To work hard
随着干燥过程的进行,生球的()将发生收缩。