如图所示,当体操运动员从高处落下,与蹦床接触的过程中,蹦床表面发生 ,而获得 能。
形变;弹性势
—Where was the boy taken away by the UFO?
—Oh, it was in the lake ______ he was swimming.[ ]
A. that
B. where
C. because
D. at which
. The prices have been going up, so that the richer you get, the less rich you are than ________ you think you ought to be.
A.that
B./
C.what
D.which