The un-flammable components in coal are water and ( ).

[单选题]The energy stored in coal ______.

[单选题]New Coal Corp. (NCC) is a small company that claims to have a proprietary f

[单选题]A．s there is less and less coal and oil, scientists are exploring new ways of making use of ____ energy, such as sunlight, wind and water for power and fuel.A． primary B. alternative C. instant D. unique

[问答题] 煤层(coal bed)是？

[单选题]What is a by-product of burned coal?A． Aluminum, silicon, and magnetic.B． Paving material.C． Fly ash.D． Concrete additive.

[问答题] Reasons for the British coal mining is called a “sick” industry today.

[单选题]E．very few years, the coal workers ______ their lungs X-rayed to ensure their health.A． are havingB． haveC． have hadD． had had

[单选题]Which of the following components are used to convert alternating current produced in the generator windings to direct current?A．Armature and equalizerB．Commutator and brushesC．Rotor and interpolesD．Field and exciter

[单选题]The three basic components of a fire are chain reaction, heat, fuel, and ____.A．carbon monoxideB．oxygenC．carbon dioxideD．any gaseous substance

[单选题] (73) manages the other components of a computer system.(73)A．BusB．Application systemC．Operating systemD．Disk