What on earth?:D
Science History
World Geography
Water Bodies
Medical stuff
100

The prime meridian is named after this place, where the Royal Observatory is located.

Greenwich

100

他发明了地动仪和浑天仪

张衡

100

The largest desert in the world (excluding Antarctica)

The Sahara desert
100

The largest lake in the world

Caspian Sea

100

The symptoms of this common illness include severe headache, nausea, and vomiting. 

Migraine

200

The most abundant element in air

Nitrogen

200

He found that the earth orbits around the sun.

Nicolaus Copernicus

200

This country has the most elongated shape of all countries.

Chile

200

A shallow body of water separated from a larger body of water by a barrier is called:

lagoon

200

This sleep disorder can cause a sudden total loss of muscle control.

Narcolepsy

300

The length of the earth's equator.

40,000 km

300

他是历史上第一个把 Pi 的值计算到3.1415926与3.1415927之间的人。

祖冲之

300

This canal connects the Pacific and Atlantic Oceans

The Panama Canal

300

This lake has more freshwater than any other water bodies on earth.

Lake Baikal

300

The flag indicating that a ship is under quarantine has these two colors.

yellow and black

400

The distance between the earth and the moon.

380,000 km

400

The first source of non-organic power harnessed by mankind is

Steam power

400

This part of the UK is not on the island of Great Britain.

Northern Ireland

400

This lake is the largest freshwater lake on earth.

Lake Superior

400

This part of the human brain controls the automatic functions of the human body.

brain stem

500

Hydraulic fracturing can harvest gas and oil from this rock formation in the earth's crust.

shale

500

He invented the petroleum-based automobile.

Karl Benz

500

This country is the largest among the Gulf Countries.

Saudi Arabia

500

The percentage of freshwater in all the water on earth 

2.5%

500

The deficiency of this nutrient will cause the disease of scurvy. 

Vitamin C