Pick up the correct statement from the following: A. Air screw converts the energy given by the engine into speed B. The propellers which are driven by turbine engines, are technically called turboprops C. The aircrafts which obtain the thrust directly from turbine engine, are called turbo-jets D. All the above

The correct answer is D. All the above.

Air screws convert the energy given by the engine into speed. This is done by the propeller blades, which are shaped like airfoils. When the propeller rotates, the blades create lift, which pushes the aircraft forward.

The propellers which are driven by turbine engines, are technically called turboprops. A turboprop is a type of aircraft engine that uses a gas turbine to drive a propeller. The gas turbine is powered by burning fuel, and the propeller provides thrust to the aircraft.

The aircrafts which obtain the thrust directly from turbine engine, are called turbo-jets. A turbojet is a type of aircraft engine that uses a gas turbine to produce thrust. The gas turbine is powered by burning fuel, and the exhaust gases from the turbine are accelerated through a nozzle to produce thrust.

In conclusion, all of the statements in the question are correct.