— Where is your mother, Peter?

— She ____ to the supermarket. She will come back soon. [ ]

A. has gone

B. goes

C. has been

D. will go

平板龙骨是船底结构中的强力构件，它应在船长范围内：（）

A.宽度与厚度均不变

B.厚度不变

C.宽度不变

D.宽度与厚度随位置不同而有所不同