Don’t sit on the chair. There ________ on it.

---I saw Betty       to Grandpa Li's home just now.---Yes. She’s often seen _________ the old man with the housework.

—Have you heard that Tom, along with his parents, _____ to Japan?—Really? No wonder I haven’t seen him these days.

Now the number of Chinese people working in Africa       more than one million.

 E-mail, as well as the telephone, ___________ an important part in daily communication.