In some cities the traffic police use computers to keep the traffic________smoothly.
Tim is one of the boys who _____ to join the school football team.
The policemen entered a lonely village near Nam Co Lake, ______ they believed the suspect(嫌疑犯) was hidden somewhere.
Most of the Chinese people are big savers — they get used to putting every penny in the bank ______ a rainy day.
—Would you like to play basketball with me now?—I’d like to, but I must have my work _______ today.
—How did you work out the Math problems?—Not able to ________ such difficult problems on our own, we had to turn to the teacher for help.