6.4 present perfect, present perfect continuous 1. Carlos has called / has been callingsix times this morning, so you’d better ring him. 2. Ii bhave left / have been leaving several messages with your secretary but. 3. Wei bhave only received / have only been receiving three pages of your six-page fax. Could you send the last two pages again please. 4. I apologize for the delay in responding but Dr Huria has left / has been leaving our institute. 5. Ii bhave tried / have been trying your Skype number several times, but Ii bhave had / have been having no success. 6. Sorry but we have had / have been having emailing problems. 7. Ii bhave written / have been writing emails all morning – Ii bhave written / have been writing 20 so far. 8. They have known / havebeen knowing each other since they were at college together. 9. I hear you have had / have been having problems uploading your manuscript. Ii bhave spoken / have been speaking to the systems manager and she has assured / has been assuring me that she will contact you by midday today. 10. Ii bhave tried / have been tryingto ring you all morning, where are you I just wanted to tell you that Ii bhave started / have been starting working on the new project. In fact, we have worked / have been workingon it for three months and we have already achieved / have