(2013·北京高考)________ the course very difficult, she decided to move to a lower level.

(2013·临沂二模)The patient's family has expressed their ________ to the press in letters for the money raised.

I must have slept in an ________ position. I'm aching all over!

If you are in trouble，Mike is always willing to________a hand.           

 Best of all, with online education, we can stick to our jobs and at the same time study and _______the latest knowledge.