For human survival, approximately what percentage of the air must be oxygen?
a. 21 c. 54
b. 77 d. 42
A
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Si la fuente de voltaje de un circuito suministra 240V y la resistencia es de 20 ohmios, la corriente es de _____ amperios.
a. 6 b. 12 c. 20 d. 120
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Blanket insulation is in the form of flexible rolls or batts usually made of ____ wool.
A. steel B. nylon C. fiberglass D. natural
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NEC identifies ____ types of rigid PVC conduit.
A. two B. three C. five D. ten
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Before disconnecting a tool from an operating air compressor, it is important to _____.
a. shut off the compressor b. close the regulator valve to that line c. make sure the tool is running d. alert co-workers
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