A cast steel strong back is fitted in way of the combustion space to help absorb _____.A.f

A．flame temperature

B．fuel oil

C．air movement

D．gas force

Concrete is strong in compression but weak in tension. Therefore, reinforcement is needed to resist the tensile stresses resulting from the loads. Additional reinforcement is occasionally used to reinforce the compression zone of concrete beam sections. Such steel is necessary for heavy loads in order to reduce long-term deflections. Reinforce concrete systems are composed of a variety of concrete structural elements that, when synthesized, produce a total system. The components can be broadly classified into: floor slabs, beams, columns, walls, and foundations. Beams are the structural elements that transmit the loads from floor slabs to vertical supporting columns. They are normally cast monolithically with the slabs and are structurally reinforced on one face, the lower tension side, or both the top and bottom faces.

The connecting rod is made of ______.

A cast iron

B forged alloy steel

C aluminum-alloy

D sheet steel

A、carbon steel

B、alloy steel

C、cast iron

D、tool carbon steel

The existing steel and cast iron rods have the same diameter.Considering both carrying capacity and economic benefits,the rational selection of the two rods of the illustrated structure is().现有钢、铸铁两种棒材，其直径相同，从承载能力和经济效益两方面考虑，图示结构两杆的合理选材方案是。

A、Rod 1 is steel and rod 2 is cast iron

B、Rod 1 is cast iron and rod 2 is steel

C、Both rods are steel

D、Both rods are cast iron

made of , and a upper part, which is referred to as and made of .

A.low-half, cast iron; top-half, heat-resistant steel

B.low-half, aluminum; top-half, stainless steel

C.piston skirt; cast iron; piston crown; heat-resistant steel

D.piston skirt; aluminum; piston crown; stainless steel

Pistons for modern engines are made of _______.

A cast iron

B steel

C aluminum-alloy

D tin-alloy

o be very stiff and tough. The material used for its manufacture is a special alloy steel, which is either cast or forged into shape.(翻译)

crank throws.

A.being shrunk into

B.to be shrunk into

C.to be shrunk with

D.shrinking into