题目

乙酸（CH3COOH）是食醋的有效成分。下列关于乙酸的说法，正确的是 A．乙酸由4种元素组成     B．一个乙酸分子中含有8个原子     C．乙酸分子的相对分子质量为60 g D．乙酸分子中碳元素与氧元素的质量比4:3 答案：B阅读理解. The Pancake Race 　　At Olney，a small town in England，Shrove Tuesday is Pancake Day．The race is said to first have been run there in 1445 and more or less ever since with occasional interruption as, for example, during the Second World War. 　　It is a race for women only. They must be housewives and live in the area．They have to cook a pancake in the air three times as they run. They have to wear aprons and cover their heads with a hat or a scarf. A bell rings twice for the women to start making their pancakes and then again for them to gather in the square, carrying their cooked pancakes in a frying pan. There they wait for the bell to ring again, and the race starts. Sometimes one of the pancakes drops on the ground, but the runner is allowed (允许) to pick it up. The winner and the runner-up both get a prize from the vicar who is waiting at the church door. The official, who helps to look after the church, gets a kiss from the winner and often her pancake as well. Then all the runners take their frying pans with the pancakes into the church and a short service is held． 　　The pancake race, with the women frying along, throwing and trying to catch their pancakes, provides(供给) a great deal of enjoyment and is frequently (时常地) shown on television in 1950, a similar pancake race was organized in Kansas, USA, and has continued(继续) ever since. It takes place on the same day, at exactly the same time. Times are clocked in both sides of the Atlantic and there is a close competition to see whether the British women or American housewives run faster. 根据短文内容，选择正确答案. （1）It is believed that the pancake race ________. ［　　］ A．has been beld every year since 1445 B．dates back (回溯至) to the 15th century C. originated in the 14th century D．started after the Second World War （2）The race is only open to women who ________. ［　　］ A．are staying in the area B．got married in Olney C．run a home in the area D．were born in Olney （3）During the race, the competitors have to ________. ［　　］ A．jump three times and catch a pancake B．throw the pancakes to each other C．throw some pancakes into a frying pan D．throw and catch their pancakes （4）When the race is over, all the runners ________. ［　　］ A．are given good prizes B．serve pancakes in the church C．go into the church to have a rest D．take part in a service （5）Since 1950, women in Kansas, USA, have ________. ［　　］ A．taken part in the Olney race B．clocked up a Pancake Day record C．competed against the Olney women D．organized other Pancake Day activities