他幼时得过小儿麻痹症后双腿安上了支架。He wore leg braces after polio in childhood.他把牵引支架固定在船体上。He fixed the towing cradle round the hull.这墙可以作为你的照相机的支架.This wall will do as a rest for your camera....
Isoamyl butyrate was synthesized by using ceric sulfate as the catalyst.以硫酸高铈为催化剂,正丁酸和异戊醇为原料合成了正丁酸异戊酯.Isoamyl butyrate was synthesized by using gallium sulfate supported on silica gel as the catalyst.以自制的硅胶固载硫酸镓为催化剂,正丁酸和...