It is believed that a new kind of drug by the scientists and they are hopeful that they w

问题补充：

It is believed that a new kind of drug by the scientists and they are hopeful that they will succeed in a few months.

A. has been developed

B. is being developed

C. is developing

D. has developed

答案：

A. has been developed

(答案→)B. is being developed

C. is developing

D. has developed

解析： 考查时态和语态。主语drug和动词develop是动宾关系，所以要用被动语态，排除C,D；根据they will succeed in a few months，可知还没有开发出来，所以不能用现在完成时态，选B，正在被开发。