下列计算正确的是[ ]

A．x⁵﹣x⁴=x

B．x+x=x²

C．x³+2x⁵=3x³

D．﹣x³+3x³=2x³

She’s______ to be a teacher when she______ her studies.[ ]

A. goes, finishes

B. going, finishes

C. go, finish

D. going, will finish