The report given by the Italian team might provide evidence that ______.
A. two things far apart might vibrate in unison
B. the ripples in space-time are only imagined
C. there exist gravitational waves
D. abrupt, violent cosmic events lead to gravitational waves
查看答案
Which of the following is not the reason why Lyderic Bocquet suppose that spin is important？
A. Because it keeps the stone fairly flat from one bounce to the next.
Because the spin can create a gyroscopic effect.
C. Because the gyroscope can prevent the stone from tipping and falling sideways into the water.
D. Because the spin can reduce the water drag.
According to Lyderic Bocquet, which of the following is NOT mentioned as a factor influencing the bounces of a stone on water？
A. The clearness of the water.
B. The gravity of the Earth.
C. The shape of the stone.
D. The speed and spin.
Which of the following certificates do you have to show for cashing your checks？
A. passport
B. credit card
C. I.D.card
D. bank book
What kind of metal did the Swiss team use to calculate the G's value？
A. gold
B. silver
C. mercury
D. lead
微信支付 
支付宝支付