1. — ________Who is there?
— ________Helem A. She’s B. That’s C. It’s D. There’s 答：C。it指人 2. It’s no good _________ today’s work till tomorrow. A. to put off B. putting off C. put off D. to be put off 答：B。it是形式主语，在It is good (use)句型中，真正主语用动名词。 3. It takes the spaceship more than three days to ______ the moan. A. to send B. being sent C. to be sent D. sending 答：C。讧是形式主语，真正主语是不定式，此处应用不定式的被动式。 4. Is ______necessary to tell his father everything? A. it B. that C. what D. he 答：A。it用作形式主语。 5. ________In summer the weather is terribly hot in Nanjing. A. Soisit B. Soitis C. Itisso D. ltsois 答：B。it指天气。强调同一件事不用倒装。 6. I find ______ simple to learn to drive a car. A. its B. it C. he D. him 答：B。it为形式宾语。 7. It is nearly half a century________ the first computer was invented. A. since B. when C. that D. until 答：A。it指时间。 8. Her uncle has moved to Beijing and does not live with her. ________ her mother. A. Neither does B. So has C. Nor has D. So it is with 答：D。表示“某人也……”时，当苗句中含不同的谓语动词，用so it is with ....或It is the same with...句式。