“有中心”的英语？

其它形式为不对称的舵控制的筏和有中心舵的对称 筏.Other types are the asymmetrical, rudder - controlled raft and the symmetrical raft with central helm ( oars ) .每个段落要有中心主旨,每句话要有主词、动词.Be sure each paragraph a central idea and that each sentence ...