B. Past perfect tense
Объяснение:
1)Plate tectonics is a modern scientific understanding of the structure and movement of the lithosphere, according to which the earth's crust consists of relatively integral blocks - lithospheric plates, which are in constant motion relative to each other.
2)The Earth is made up of four layers: the inner core in the centre the outer core around it, the matle and the crust on the surface.
3) The location bellow the Earth's surface where the earthquake starts is called the hypocentre.
4)Scientists use a spacial instrument called a seismograph and a system called the Richter scale to record and measure the strength of an earthquake.
5)More than a million earthquakes accur every year, but most of them are minor and people don't feel them
100% правильно.
14. I ... this book yet when the phone rang
b. had not read ( я ещё не прочитал книгу, когда телефон зазвонил—первое действие предшествует второму )