I . 单句语法填空 1 . — Hello, I ________ (phone) to ask if I can book two tickets for tonight's film. — Sorry, we've already sold out. 2 . Jack ________ (work)in the lab when the power cut occurred. 3 . At college , Barack Obama didn't know that he ________ (become) the first black president of the United States of America. 4 . Please don't give me a call between 9 ∶ 00 and 11 ∶ 00 tomorrow.I ________ (have) a meeting then. 5 . Attracted by the unique way of communicating, many foreigners ________ (join) in sending and grabbing red packets so far. 6 . During his stay in Xi'an, Jerry tried almost all the local foods his friends ________ (recommend) . 7 . The woman from Jiangsu Province ________ (make) shoes since she was 19 years old, and this year marks her 31st year making cloth shoes. 8 . Despite the previous rounds of talks , no agreement ________ (reach) so far by the two sides. 9 . In the 1950s in the U . S.A. , most families had just one phone at home, and wireless phones ________ (invent) yet. 10 . I had a strong desire to go in and play with the toy, but ________ (hold) back by the shop window.