to the ratio between composite materials and structural weight, which
of the following used most composite materials? ____.
A: F-22
B: A380
C: A400M
D: B787
举一反三
- According to source, composite materials divided into: （） A: conductive composite materials B: natural composite materials C: artificial composite materials D: damping composites
- The<br/>safety coefficient of the capacity of composite materials is usually<br/>____ times of metal materials. A: 0.8-0.9 B: 1.0-1.25 C: 1.15-1.2 D: 1.5-2.0
- Building materials may be classified into three groups according to the purposes they are used for: structural materials, decoration materials and some special materials.
- During<br/>the development and application of the composite materials, we should<br/>put ____ as the top priority. A: Designability B: Safety C: Adaptability D: Cost-effective
- 1-4.Strictly<br/>speaking, structural materials are also a type of functional<br/>materials, which belong to a large category of mechanical functional<br/>types. ()
内容
- 0
Composite materials have been in existence for many centuries. The earliest man-made composite materials were straw and mud combined to form bricks for building construction.。（ ）
- 1
Composite materials are mixtures of two or more materials._
- 2
A composite is composed of two (or more) individual materials, which come from metals, ceramics, and polymers.
- 3
Most composite materials consist of a selected or reinforcing material and a compatible resin to obtain the specific characteristics and properties desired.
- 4
Which of the following expressions is correct? A: Carbonaceous materials are the most widely used cathodes because they are non-toxic and provide good stability. B: Carbonaceous materials are the most widely used cathodes because they are non-toxicity and good stability. C: Carbonaceous materials are the most widely used cathodes due to their non-toxicity and high stability. D: Carbonaceous materials are the most widely used cathodes due to non-toxic and highly stable.