Thanks for your reply.
Actually, I attempted to use the Adobe Lightroom plugin for importing my photos, however it says that I do not have enough space in my hard disk, how come? I thought that Lightroom only uses the same Aperture library. It seems that it makes a copy of all my library. I changed the Options in the Options dialogue box, but it still shows the same. What do you suggest to do? Is there a chance to only import my photos to Lightroom without making any copy? Obviously if I make a copy in the same hard disk it will be run out of space and the same issue will appear.
Look forward to hearing from you,
The plugin which you are using, it will extract all the files from Aperture Library to your computer.
If you do not have sufficient space on your computer, I would suggest you to upgrade your computer or you can also get a external storage device to save the images from Aperture Library.
Hope this helps.