In which stage of sewage treatment, large amount of air is pumped into it?

Read the following paragraph and answer the given questions:
DRUGS AND ALCOHOL ABUSE
The drugs, commonly abused are opioids, cannabinoids, and coca alkaloids. Opioids are the drugs, which bind to specific opioid receptors present in our central nervous system and gastrointestinal tract. Heroin, commonly called smack is chemically diacetylmorphine which is a white, odourless, bitter crystalline compound. Cannabinoids are a group of chemicals, which interact with cannabinoid receptors present principally in the brain. Natural cannabinoids are obtained from the inflorescences of the plant Cannabis sativa. The flower tops, leaves and the resin of cannabis plant are used in various combinations to produce marijuana, hashish, charas and ganja. Generally taken by inhalation and oral ingestion, these are known for their effects on cardiovascular system of the body. It interferes with the transport of the neuro-transmitter dopamine. Cocaine, commonly called coke or crack is usually snorted. It has a potent stimulating action on central nervous system, producing a sense of euphoria and increased energy. Excessive dosage of cocaine causes hallucinations. Other well-known plants with hallucinogenic properties are Atropa belladona and Datura. These days cannabinoids are also being abused by some sportspersons. Drugs like barbiturates, amphetamines, benzodiazepines, and other similar drugs, that are normally used as medicines to help patients cope with mental illnesses like depression and insomnia, are often abused. Morphine is a very effective sedative and painkiller, and is very useful in patients who have undergone surgery. Several plants, fruits and seeds having hallucinogenic properties have been used for hundreds of years in folk-medicine, religious ceremonies and rituals all over the globe.
Which one of the following drugs is known for its effects on the cardiovascular system of the body?

Which one of the following is NOT a correct feature of Homo erectus ?

The natural interconnections of food chain is :

Arrange the given geological periods according to their occurrence from oldest to latest order?
(A) Devonian
(B) Cretaceous
(C) Triassic
(D) Carboniferous
Choose the correct answer from the options given below:

The exine of pollen grains is made up of :

Wings of an insect and wings of a bird are :

A conducting ring of radius \(r\) in a magnetic field varying at rate \(x\) has electric field intensity at any ring point as :

If \(f(x)=\left\{\begin{array}{ll}a x-1 & \text { if } x \geq 1 \\ 2 x+1 & \text { if } x<1\end{array}\right.\) is continuous at x = 1, then a equals

Read the following passage carefully and answer the given questions.
Cancerous cells just continue to divide giving rise to masses of cells called tumors. Benign tumors normally remain confined to their original location and do not spread to other parts of the body and cause little damage. The malignant tumors, on the other hand are a mass of proliferating cells called neoplastic or tumor cells. Transformation of normal cells into cancerous neoplastic cells may be induced by physical, chemical or biological agents. Ionising radiations like X-rays and gamma rays and non-ionizing radiations like UV cause cancer. Cancer-causing viruses are called oncogenic viruses which have viral oncogenes. The substances to which an immune response is produced are called allergens. The antibodies produced to these are of IgE type. Common examples of allergens are mites in dust, pollens, animal dander, etc. The primary lymphoid organs are bone marrow and thymus. The secondary lymphoid organs provide the sites for interaction of lymphocytes with the antigen, which then proliferate to become effector cells.
The tumors that remain confined to their original location and do not spread to other parts of the body are:

An annuity in which the periodic payment begin on a fixed date and continue forever is called:

A thermal power plant produces electric power of 1000 kW at 10000 V, which is to be transmitted 20 km away from the power plant. The transmission line has resistance of 0.5 ohm per kilometre, the percentage power dissipation during transmission is :

In Kolbe's reaction, phenol undergoes :