[单项选择]Nearly all trees have seeds that fail to the earth, take root, and eventually______
A. generate new seeds
B. new seeds generated
C. generates new seeds
D. new seeds are generated

[填空题]Most theories about the evolution of Earth have the same general point of view.

[单项选择]Does everyone on earth have an equal right （　） an equal share of its resource
A. by
B. at
C. to
D. over

[单项选择]Humans on the earth have had an over-inflated view of how far the planet’s atmosphere extends into space. It turns out that the ionosphere (电离层), the layer of electrically charged particles that comprises the outer atmosphere, is thinner than expected-and cooler.
Understanding the shape and size of the ionosphere is an important first step in figuring out how particularly dense regions within it may distort radio, radar and navigation signals. Such distortions can make communications and satellite-based systems less reliable.
"In order to predict how severe those distortions will be, it’s necessary to know how big those structures in the ionosphere are and where they exist," Roderick Hellis, with the Space sciences Center at the University of Texas in Dallas, told Discovery News.
Hellis and his colleagues have been using a suite of NASA instruments called CINDI, which fly on the U.S. Air Force Communication/Navigation Outage Forecast System (C/NOFS) satell
A. how far away the upper edge of the ionosphere is
B. how many particles comprise the ionosphere
C. how long the ionosphere has been existing
D. how the ionosphere extends into space

[单项选择]Does everyone on earth have an equal right （） an equal share of its resources.
A. by
B. at
C. to
D. over

[单项选择]