A:valuable for
B:value to
C:of value to
D:of value for
把肯定句改成否定句
①我们都举手赞同。 ②这件事一定得去他办。
硝酸铵受热或高温条件下易分解,其反应化学方程式为:2NH4NO3=2N2↑+O2↑+4X,则X的化学式为( )
Terry and his team members were the first how the disease spreads from animals to humans.
反射和反射弧的关系是( )
如图△ABC中,∠C=90°,AD平分∠BAC,AB=5,CD=2,则△ABD的面积是____.