下面是南宋地方官就近年江南农业发展情况向朝廷作的汇报，查明属实的是

①引进优良品种占城稻，并加以推广②粮食产量提高，苏州、湖州成为重要粮仓

③棉花的种植扩展到长江流④茶树的栽培有很大发展，江南新辟了许多茶园[ ]

A、①②

B、②③

C、②③④

D、①②③④

Gunpowder is generally believed __________ in ancient China.

A．to have invented

B．being invented

C．to have been invented

D．having invented