DO ALL VOLCANOES ERUPT?
Some volcanoes are always erupting. They are called active volcanoes. Mount Etna in Italy is an active volcano.
Some volcanoes have not ______(4) ______ since prehistoric times. These are called extinct volcanoes. Most of the Hawaiian Islands are extinct volcanoes. These volcanoes ___(5) ______ have a hot spot under them. They cannot erupt anymore.
Some volcanoes have not erupted for a long time, so they could erupt again. These are called dormant volcanoes.
Scientists try to figure out when volcanoes will erupt. Studying volcanoes is hard and dangerous work. Scientists drill into volcanoes. They create maps of the inside of the volcanoes. They use satellites to study volcanoes in space. Scientists have been able to predict a few eruptions, _____(6) ______it is not easy to tell what a volcano might do.
(4)
A. burnt
B. erupted
C. been erupted
D. been burnt
Giải bởi Vietjack
Chọn đáp án B
- erupt (v) phun trào
- cấu trúc thì hiện tại hoàn thành: have/ has + VpII
Dịch: Một số núi lửa đã không phun trào kể từ thời tiền sử.
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Mark letter A, B, C or D to indicate the word whose main stress position is placed differently from that of the others in each group
Mark letter A, B, C or D to indicate the word whose main stress position is placed differently from that of the others in each group
In the early years of television, educational specialists believed that it would be very useful in teaching and learning. Many schools have bought television sets, intending to use them effectively to improve the quality of education; but actually, they are rarely used properly in classrooms. Meanwhile, children spend the majority of their out-of-school hours watching TV and their typical school days proceed as if television did not exist.
There are some explanations for the failure of television to get the interest of the teachers. Firstly, the schools that purchased television sets have not set aside money for equipment repairs and maintenance, so these television sets are sooner and later out of order. Secondly these schools have not found an effective way to train teachers to integrate television into their ongoing instructional programs. Lastly, most teachers do not regard the quality of television and its usefulness in the classroom.
Teachers at the schools work hard for at least twelve years to train their students to become good readers. However, according to recent statistics, teenagers seldom spend their free time reading books and newspapers but watching television instead.
These volcanoes ___(5) ______ have a hot spot under them. They cannot erupt anymore.
