Read each of the following passages and answer the items that follow. Your answers to these items should be based on the passages only.
Vehicular pollution accounts for more than 70 per cent of carbon monoxide generated in the three metropolitan cities—Delhi,
Bombay and Kolkata. This poisonous gas, emitted by petrol-driven vehicles in the form of exhaust, is much more toxic than the exhaust ot the diesel-driven vehicles such as trucks and buses.
Dr. H.B. Mathur, Professor in the Department of Mechanical Engineering in the Indian Institute of Technology, Delhi, currently working on devices to control gaseous pollution, speaking at a seminar on “Environment, Development and Law in the Developing Countries” in the capital on Saturday, said that controlling the gases emitted by petrol-driven vehicles was crucial for ensuring healthy environment in the metropolitan cities. But besides carbon monoxide there are other hazardous gases in the air like hydrocarbons, and oxides of nitrogen that have crossed the desired limit.
Things are, however, only going to get worse in the next decade with vehicular traffic increasing manifold. It is estimated that there will be a sixfold increase in the number of motorcycles, scooters and tempos, a threefold increase in the diesel powered trucks and buses and almost twofold increase in the number of gasoline-operated vehicles on roads.
Immediate measures thus need to be taken to check growing degradation of the environment. The available techniques involve oxidation of the hazardous gases in the exhaust chamber itself by supplying additional oxygen, or alternatively using catalysts.
The formation of carbon monoxide is directly related to air-fuel ratio. If formed, it may be eliminated by further oxidation, either thermally or catalytically. The formation of oxides of nitrogen can be minimized by lowering the combustion temperature.
Dr Paul C. Njoku of Department of Electrical Engineering, Indian Institute of Technology, Delhi, on the other hand, suggested that alternative fuels should be used. He gave the example of natural gas engine technology which has considerably advanced in the recent times.
Dr Njoku said almost all the CNG-powered vehicles on roads today are conventional gasoline fuelled vehicles that have been converted to duel fuel operation.
Read the above text carefully to answer the following questions.
The toxic gases mentioned in the passage is/are