The leaves are _________ the tree.[ ]
A. on
B. in
C. at
答案：A
Japan’s economy _______ in the past twenty years. No one knows how long it ______ before it regains its increase.
A．has been declining; will be
B．has declined; would be
C．had been in decline; would take
D．was on the decline; will take
诊断闭经时用孕激素试验阴性可以说明( )
A．有排卵B．子宫内膜未受雌激素水平影响C．停经后有出血D．子宫内膜已受雌激素水平影响E．无排卵
