In the following passage, some words have been deleted. Read the passage carefully and select the most appropriate option to fill in each blank.
The tuatara, which lives on New Zealand's islands, is affectionately known as Living fossil. It is called that because it is the only ___(1)___ reptile in a group of reptiles that dates back about 220 million years to the time of the dinosaurs. The colour of the tuatara is grey or olive green. It ___(2)___ to a length of around 60 cm. The fact that this lizard has three eyes is its most ___(3)___ feature. The pineal eye is the name given to the cone-shaped third eye. This eye is in a space between the brain and head. It has an eyelid over the third eye, which closes on a horizontal level. The tuatara has teeth that are ___(4)___ from those of other reptiles. The lower jaw has only one row of teeth, while the upper jaw has two rows.
The tuatara is most active at night. It eats the eggs of birds, frogs, rats and insects. A tuatara's average lifespan is less than 77 years, but some species can live up to 100 years. In the spring, the female tuatara lays 8 to 15 eggs. These eggs are ___(5)___ during summer.
Select the most appropriate option to fill in blank number 1.