When drinking______ someone’s health，you raise your glasses，but the glasses should not touch．

Like some of my classmates，I cannot live up to my teachers' expectations；________，I let them down.

---How do often you go to school?---On foot_______it rains.

---Are you going ___ foot?  ----No. we’re going ___ Tom’s car.

It is amazing that the little boy can swim ________the river ________100 meters wide.