The neutrinos are hard to detect most probably because of
A. their ability to escape from different regions of space.
B. their inability to penetrate dense matter.
C. the similarity of their structure to that of nucleons.
D. the infrequency of their interaction with other matter.
查看答案
About 50 percent of the nation's electricity was generated by
A. gas-fired power plants.
B. coal-fired power plants.
C. water generated power plants.
D. wind-generated power plants.
What protects the sea dragon from a meat eater's attack？
A. Its enormous size.
B. Its plant-like appearance.
C. Its instantaneous response.
D. Its offensive smell.
Where did the mine companies operate according to the news item？
A. In 28 states, from West Virginia in the east to Montana in the west.
B. In 27 states, from West Virginia in the west to Montana in the east.
C. In 27 states, from West Virginia in the east to Montana in the west.
D. In 28 states, from West Virginia in the west to Montana in the east.
The island's rate of deafness is times greater than that of the rest of the United States？
A. seventy
B. seventeen
C. twenty-five
D. Thirty
微信支付 
支付宝支付