Selina has recently ___________ Chinese painting to please her grandmother who was born in China．

A．taken on

B．taken off

C．taken up

D．taken over．

下列执行器中，（）是旋转式的调节阀，具有优良的密封性和安全可靠性。

A．气动薄膜双座调节阀

B．直行程式电动执行机构

C．气动O形切断球阀

D．气动偏心旋转调节阀