My desktop screan on my I Mac computer

Will it Safe Boot if you hold the Shift key...?

see > Mac OS X: Gray screen appears during startup

Can you startup from your Recovery Partition if you hold the Command R keys..?

see > OS X: About OS X Recovery

If you startup into the Startup Manager by holding the Option key, can you see and select either your Macintosh HD or the Recovery Partition...?

see > Startup Manager: How to select a startup volume