5. There are coal, oil, and metal ______ burried deep in the ground.
A: sources
B: substances
C: resources
D: properties
A: sources
B: substances
C: resources
D: properties
举一反三
- _____________ is the process of extracting coal from the ground. A: Overfishing B: Overconsumption C: Coal mining D: Burning of fossil energy sources
- Organic chemicals mainly come from oil, natural gas, and . A: metal B: air C: water D: coal
- There were resources such as coal, iron, gold, and copper deep in the soil, but they remained________. A: discovered B: to discover C: being undiscovered D: undiscovered
- Materials are _________. A: the matter of the universe B: these substances having properties that make them useful in structures and machines C: these substances having properties that make them useful in products and systems D: these substances having properties that make them useful in structures, machines, devices, products, and systems
- Materials are _________. A: the matter of the universe B: these substances having properties that make them useful in structures and machines C: these substances having properties that make them useful in products and systems D: these substances having properties that make them useful in structures, machines, devices, products, and systems.