This concept is called machine learning (36) ________ is a sub-branch of artificial intelligence. 

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 44 to 50

Due to the nature of our business, it's sometimes necessary that our staff work at night. Night shifts can be particularly demanding on employee wellbeing and health. This can include disruption to the body clock, fatigue, sleeping difficulties, disturbed appetite and digestion, reliance on sedatives or stimulants, social and domestic problems and other symptoms of ill health. To combat this, we do not have employees on night shifts for extended periods. This is because workers’ bodies will just have started to adapt to the new pattern.

We find rotation shifts every two to three days are best for workers and weekly or fortnightly rotations are the least comfortable for workers. Forward-rotating programs (moving from morning to afternoon to night shifts) are better than backward-rotating ones in terms of sleep loss and tiredness.

If someone works at night, there are rules covering the hours they work. Night time working hours are usually between 11 p.m. and 6 a.m. – but this can be flexible and should be discussed between you and us. To qualify as night working, the night time period must be no more than 8 hours long and include the period between midnight and 5 a.m. Any of our staff under 18 years are not allowed to be night workers.

We must make sure that you don't work more than an average of 8 hours in a 24-hour period. By law, you can't opt out of this working limit. We must also keep records of any night workers’ working hours to prove they aren't exceeding night working limits, and we must keep the records for at least 2 years. These records can be inspected by you at any time on request.

Our usual limits and regulations for night workers do not apply to self-employed workers. This does not include agency workers, who are treated as normal workers with us.

If you agree to working at night for us, the agreement will be put in writing. If you are to begin working at night, we must perform a health assessment before you become a night worker and on a regular basis after that. Usually, this is just done with a questionnaire, which was created in collaboration with qualified health professionals. If there are any health questions regarding your health and night work, we will offer you a follow-up examination by a health professional if you still wish to work nights.

(Adapted from IELTS 5 practice Tests – General Set 3 - Tests No. 11-15 (High Scorer’s Choise) – page 109)

“What are you going to give the name to this cat?”, asked my wife.

One of the clearest differences between depression and melancholy is that depression is an emotional state of resignation, whereas melancholy is something we even desire as it provides this time out for losing in reflection.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 39 to 43

In the early days of sea travel, seamen on long voyages lived exclusively on salted meat and biscuits. Many of them died of scurvy, a disease of the blood which causes swollen gums, livid white spots on the flesh and general exhaustion.

On one occasion, in 1535, an English ship arrived in Newfoundland with its crew desperately ill. The men's lives were saved by Iroquois Indians who gave them vegetable leaves to eat. Gradually it came to be realized that scurvy was caused by some lack in the sailors' diet and Captain Cook, on his long voyages of discovery to Australia and New Zealand, established the fact that scurvy could be warded off by the provision of fresh fruit for the sailors.

Nowadays it is understood that a diet which contains nothing harmful may yet result in serious disease if certain important elements are missing. These elements are called 'vitamins '. Quite a number of such substances are known and they are given letters to identify them, A, B, C, D, and so on. Different diseases are associated with deficiencies of particular vitamins.

Even a slight lack of Vitamin C, for example, the vitamin most plentiful in fresh fruit and vegetables, is thought to increase significantly our susceptibility to colds and influenza.

The vitamins necessary for a healthy body are normally supplied by a good mixed diet, including a variety of fruit and green vegetables. It is only when people try to live on a very restricted diet, say during extended periods of religious fasting, or when trying to lose weight, that it is necessary to make special provision to supply the missing vitamins.

(Adaped from the book Practical Faster Reading – A course in reading and vocabulary for upper-intermediate and more advanced students – by Gerald & Vivienne Mosback - page 93)

Mark the letter A, B, C, or D on your answer sheet to indicate the word that differs from the other three in the position of the primary stress in each of the following questions.

Mark the letter A, B, C, or D on your answer sheet to indicate the word whose underlined part differs from the other three in pronunciation in each of the following questions.