下列各句中，没有语病的一句是（ ）

We held a welcome ceremony yesterday ________ Professor John Grey who had just come and would teach in Zhejiang University.

We work together to achieve our common purpose： ________ world that is safer, cleaner and healthier than ________ one we are living in.

It wasn’t until nearly a month laterI received the manager’s reply

Cloning humans has been _____ in the science world for many years and it is likely to continue .