The girls burst out laughing when I began to make a speech, —__________,of course, made me feel embarrassed.
The lesson Mr Li gave just now was too difficult for the class to ________.
The scientists recommend that studies ________ to find out what side effects the medicine might cause.
An advertisement is useful in ________ it lets customers know of the kinds of goods in the shops.
—I need some fresh air, so I am going out for a walk. —________.
—Don't you know that a proper amount of exercise a day will ________ to a person's health? —No wonder so many senior citizens do exercise in the square.