On top of scavenging air box is mounted a strong cast iron frame for each cylinder known as（）
举一反三
- （） of the A-frames there is a strong cast iron frame called the scavenging air box.
- At the top of the A-frames there is a strong cast iron frame called （）.
- On the top of the cylinder is mounted the cylinder cover which is pressed onto （） of the cylinder liner by means of nuts and studs.
- Each set is to be put in a cardboard box, strengthened with iron straps, and then put in a wooden case. It must be strong enough to ______ the roughest handling.
- Each set is to be put in a cardboard box, strengthened with iron straps, and then put in a wooden case. It must be strong enough to the roughest handling.