Three general classes of earthquakes are now recognized: tectonic (地壳构造的), volcanic, and artificially produced, the tectonic variety is by far the most harmful, and such quakes cause particular difficulties for scientists trying to develop ways to predict them. Earthquakes of volcanic origin are seldom very large or destructive. Humans can cause earthquakes through a variety of activities.
Historical written accounts of earthquakes before the middle of the 18th century are generally rare and not reliable. The earthquake in 1556 in Shanxi Province of China, which killed about 800 000 people, was one of the greatest natural disasters in history, in north America, the series of earthquakes that struck southeastern Missouri in 1811 were probably the most powerful experienced in the united states in history.
The bad effects of earthquakes are:
Causing many people’s 46. ______.
Producing 47. ______.
The kinds of earthquakes already known to us are 48.______,49.______and man-made.
The place that the earthquake which resulted in about 800 000 people’s death:
50.______. 48().
Earthquakes can cause great loss of life by destroying structures such as buildings, bridges, and dams, and they can also produce erous landslide (山崩). Another destructive effective effect of earthquakes is the genetation (振荡) ,usually by sub-sea tremor(振动),or so-called tidal waves. Their towering walls of water have struck populated coastlines so violently that entire towns have been destroyed.
Three general classes of earthquakes are now recognized: tectonic (地壳构造的), volcanic, and artificially produced, the tectonic variety is by far the most harmful, and such quakes cause particular difficulties for scientists trying to develop ways to predict them. Earthquakes of volcanic origin are seldom very large or destructive. Humans can cause earthquakes through a variety of activities.
Historical written accounts of earthquakes before the middle of the 18th century are generally rare and not reliable. The earthquake in 1556 in Shanxi Province of China, which killed about 800 000 people, was one of the greatest natural disasters in history, in north America, the series of earthquakes that struck southeastern Missouri in 1811 were probably the most powerful experienced in the united states in history.
The bad effects of earthquakes are:
Causing many people’s 46. ______.
Producing 47. ______.
The kinds of earthquakes already known to us are 48.______,49.______and man-made.
The place that the earthquake which resulted in about 800 000 people’s death:
50.______.
