I'm getting that too with Chrome. I'm assuming it's transient, so not stressing too much. My work-around is to navigate away from the lesson page, then return. When I restart, I fast-forward to where I was. But, yes, annoying.
See if this method works..it does 90% of the time for me...so at the beginning of every lesson, I let the video run for 5 secs and then pause it, it buffers and does not give the error...
... the second condition, contradicting the truth of the condition. According to ... />
If you can contradict the truth of the second condition, then ...
Yep. Start from the top and go down. Depending on your schedule and the amount of time you can put into the studying, make sure to review each lesson until there is no hinderance of a doubt you have mastery over it.
... scientific reading passages (phenomena explanation lesson..). etc. Maybe go back and ... me , that grammar lesson (oh man that grammar lesson) lawgic lessons, explanation ...
...
There's a lesson on embedded conditionals:
http ... ://7sage.com/lesson/mastery-embedded-conditional
...
Also a lesson on negating conditionals:
http ... ://7sage.com/lesson/advanced-negate-all-statements/< ...