---What do sharks eat, do you know?

---Many sharks ______ fish, other sea animals.

---The traffic is always busy ______ the rush hour.

---So we'd better leave a little earlier.

---What do you ______ the football match?

---It's really exciting. Both of the teams played very well.

---You shouldn't throw anything away on the ground.

---You are right. We should keep our classroom ______.

---Did you ever ______ trees on the hill?

---No, never, I know it's very important to protect our environment.

--Will you watch the World Cup match this year?

--No, but I ________ several World Cup matches since I was a small child.