（） of the A-frames there is a strong cast iron frame called the scavenging air box.
举一反三
- On top of scavenging air box is mounted a strong cast iron frame for each cylinder known as（）
- At the top of the A-frames there is a strong cast iron frame called （）.
- 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.
- In addition to iron and carbon, list the other elements that may be found in a grey cast iron and describe their effect on the properties of a grey cast iron.