What mistakes are in the following paragraph?
Then the research group formally started working on professional e-learning solutions, virtual learning environment, electronic content, training tools, mobile learning.
hen the research group formally started working on professional e-learning solutions, virtual learning environments, electronic content, training tools and mobile learning.
Hi , i want realy to know what is the difference between present perfect and present perfect continous when exactly we can use one of them because i realy confused between the two especially in speaking so help me with examples ./
best regards
zazi 