某金属的逸出功为W，现在用波长为λ的光照射能发生光电效应，普郎克常数为h，光速为

特种储蓄存单能否通兑？

21． More than one high official_____by the police since the mayor war shot dead.

A．has been questioned

B．have been questioned

C．was questioned

D．were questioned

汽油的燃烧值为4.6×10⁷焦耳/千克，要获得2.3×10⁸焦耳热量，需要完全燃烧______的汽油．

早产儿外观特点下列哪项是错误的（）

A.头发乱如绒线头

B.软骨软，耳舟不清楚

C.足纹遍及整个足底

D.乳腺无结节

E.指甲未达指尖

第一枚奥运柔道女冠军是谁？