It be the vocabulary that caused you the problem in the exercise because you know a lot of words.
Seeing that the drowning child was struggling in the icy water, the soldier dived into the river without hesitation, ___ his own safety.
If you just spend your time___ gains and losses, maybe you'll get nothing in the end.
According to the newly-made traffic regulation, whoever drives through red light be fined at least 200 dollars.
He is very popular among his students as he always tries to make them ____ in his lectures.
I'm afraid I'm not ___ to help with the show, for I am fully occupied with my own project