86. Birds owe their remarkable abilities to ____.

1. inheritance
2. insight
3. intelligence
4. navigation

87. The superior intelligence of monkeys, compared with other creatures, apart from man, is demonstrated by ____.

1. the possession of brains
2. the ability to reason and think
3. the memory
4. the ability to cope with abstract ideas

88. Monkeys show their superiority in intelligence over other creatures apart from man by ____.

1. being less fierce
2. piling op boxes
3. remembering lighted doors
4. developing their own methods for solving problems

89. Monkeys are differentiated from man because they lack our ability to ____.

1. draw water from a pond
2. understand abstract ideas
3. stop short and consider difficult problems
4. use water to put out fires

90. Kobler's monkey is "charming" because the monkey ____.

1. chose Kobler himself as the quickest route
2. successfully completed the experiment
3. took Kobler by the hand
4. used all the gear provided

(Reference keys.)