In some languages,100 words make up half of all words ________ in daily conversations.
We're considering students' request ______the school cafeteria should provide more kinds of food.
—Oh, doctor, The wound on my leg is infected. —You really shouldn’t have left it _______ to the sun.
____ you call me to say you are not coming, I will see you at the theatre at five this afternoon.
—Would you rather come on Friday or Saturday?—________________.
Relax yourself every day, ________ you'll be too tired to get good grades.