胶带运输机的驱动装置布置有哪些类型？
参考答案：
胶带运输机的驱动装置布置有头部驱动、头尾驱动、多驱动三种类型。
He made another wonderful discovery, _______ of great importance to science.
A．which I think is
B．which I think it
C．which I think it is
D．I think which is
（1）写出乙酸与乙醇在浓硫酸、加热条件下发生酯化反应的化学方程式 ▲
（2）写出SO2通入足量NaOH溶液中反应的离子方程式 ▲
