Softening Claims” Using natural gas instead of coal ______ prevent air pollution”

Softening of the bones caused by a deficiency of vitamin D, either from a poor diet or lack of sunshine or both is ________. A: osteoblast B: osteomalacia C: chondromalacia D: chondrogenesis

The hot-melt glass is made by using a special hot-melt furnace to heat the glass above the softening point, and then the flat glass is molded in a special molding die, and then annealed. A: 正确 B: 错误

What is the most common changes of infants within six months with vitamin D deficiency of rickets () A: hand and foot bracelet B: rib valgus C: skull softening D: chicken breast E: O-shaped legs

During top coal caving mining, the essential cause of top coal crushing is ( ). A: softening of water in roof strata B: the stress it beared is large than its own strength C: the gas in the top coal expands, leading to breakage D: cracks produced by raw coal during its formation