Some spiders hunt on the ground, others build webs to trap their food, but the grass water spider catches its prey by running along the surface of the water.
This special water spider lives on the grassy banks of streams where mosquitoes, damsel flies and other insects come to feed and breed.
Although it is one of the largest spiders in New Zealand, it has an unusual ability. It doesn’t disturb the water as it waits for its meal, and there is barely a ripple when it skims across the surface at lightning speed to catch its prey.
Grass water spiders deal swiftly with larger insects like damsel flies by pulling their heads under the water and holding them there until they drown.
After a meal, the grass water spider spends up to half an hour grooming itself. It wipes its eight eyes, brushes its antennae, and takes special care to clean the hairs on its body.
It is the hairs that trap tiny bubbles of air so that the spider can run down a blade of grass and stay underwater for up to an hour when it is frightened. The hairs also keep the spider dry, even underwater.
It is only when the female spider is caring for the young that she does not hunt on the water. After mating, she produces a large egg sac, which she carries around for five weeks. Once the eggs start to hatch, she attaches the sac to some blades of grass or a thistle. She then tears the sac open and releases the tiny spiders into the nursery web.
The purpose of the passage is to（）
A. convince readers that spiders are dangerous
B. indicate that the grass water spider is endangered
C. list all of the spiders that can be found in New Zealand
D. describe the characteristics of the grass water spider
的0号柴油罐（柴油闪点为60℃），主厂房北750m有一座储存有氨、盐酸、硫酸、乙炔等危险化学品的化学品库。根据《危险化学品重大危险源辨识》（GB18218-2009），该厂应该划分为（）个重大危险源单元。