If the carbon content of a type of steel is 0.1%， this steel is a kind of （ ）. A: low-carbon steel B: medium-carbon steel C: high-carbon steel D: HTLA steel

are very soft ,and can be used for bolts and for machine parts that do not need strength.: Alloy steels|High carbon steels|Low carbon steels|Medium carbon steels

Auto-tempering occurs after welding when （ ）. A: carbon content of weld is low B: cooling rate is slow C: peak temperature is high D: Ms is high

For fabrication of fiber reinforced composite, in which one weak<br/>interface is desired to ensure the composite possess high toughness.(<br/>) A: Carbon fiber reinforced titanium. B: Carbon fiber reinforced carbon composite. C: Glass fiber reinforced polymer.

( ) is the highest rank of coal with highest carbon content, high heat content, low sulfur content,but limited supplies.

What might avert the danger of the building up of a high concentration of aerosols A: Nuclear power. B: Fossil fuels. C: Carbon dioxide. D: Atom bombs.

Carbon chains can rotate around a double bond (carbon=carbon or C=C).

What caused the deposits A: The hydrochloric acid broke the carbon bonds in tile carbon dioxide, B: The magnesium oxide broke the carbon oxygen bonds in the carbon dioxide. C: The burning magnesium broke the carbon oxygen bonds in the carbon dioxide. D: The gas collection method broke the carbon-oxygen bonds in the carbon dioxid

______ of agricultural practices is a recognized method of carbon sequestration as soil can act as an effective carbon sink offsetting as much as 20% of 2010 carbon dioxide emissions annually.

The synonym of CO2 is .（ ）。 A: hydrogen B: carbon monoxide C: carbon dioxide D: oxygen