圆柱的底面半径是3cm，圆柱的高是5cm，则圆柱的侧面积是（ ）cm2．（结果保留π）
30π
After he retired from office, Rogers_________ painting for a while , but soon lost
interest. [ ]
A. took up
B. saved up
C. kept up
D. drew up
防火滑阀是当发生火灾时把调节系统的油排入主油箱。（）
