用括号内动词的适当形式填空。 1. One of the boys ______ (be) born in 1990? 2. Mr Wang ______ (enter)a competition before? 3. ______ you ever ______ (write) to your friend in English? 4. My brother______ (not visit) the Great Wall last year? 5. Tom ______ (not go) to the zoo, will he? 6. I ______ just______ (finish) my homework.? 7. The boy ______ (stay) at home last night.? 8. The man ______ (be) 40 years old now.He ______ (be) in Tianjin for 20 years? 9.—Sally ______ (visit) China? —No, hasn't? 10. Lingling wants ______ (go) to the USA.