实验室里有锌和稀硫酸制取氢气，同时得到另一种物质，其化学式是______．
硫酸锌的化学式是ZnSO4．
故填：ZnSO4．
风力发电机定期维护后不必填写维护记录。（）
If your vessel is dragging her anchor in a p wind，you should（）.
A.shorten the scope of anchor cable
B.increase the scope of anchor cable
C.put over the sea anchor
D.put over a stern anchor
