假设1部手机与6辆自行车交换成功。现在手机和自行车的生产出现了以下三种情况：
①手机行业劳动生产率不变，自行车行业劳动生产率提高1倍
②手机行业劳动生产率提高1倍，自行车行业劳动生产率不变
③手机行业和自行车行业劳动生产率都提高1倍
则手机与自行车的交换比例发生的变化依次是

20世纪五六十年代是极不寻常的时期，当时面对严峻的国际形势，为抵制帝国主义的武力威胁和核讹诈，50年代中期，以***同志为核心的第一代党中央领导集体，根据当时的国际形势，为了保卫国家安全、维护世界和平，高瞻远瞩，果断地制定的决策是

阅读理解
B
    I went to Paris last August．I went there with my friend Jeff．We went by train．We stayed for five days in a small hotel in the center of Paris. The hotel was not expensive .Our room was OK—it was old，but very clean.
    In the mornings we visited all the famous tourist sights(著名的旅游景点)and museums．The Louvre Museum was my favorite ! We usually had some bread for lunch in a park．In the afternoons we walked around Paris．We took a lot of photos! And we had crepes! They were delicious! After a little sleep and a shower, in the evenings．We had dinner in small restaurants and then we went to pubs(酒吧)．We met very interesting people! We also made some good friends．
    We didn't buy any gifts．Everything was very expensive．But we sent(邮寄)very beautiful postcards(明信片)to our friends．We had a lot of fun ! It was an excellent holiday!
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new, The, have, leaves, trees, green(.)   （连词成句）

人体缺乏维生素A容易患佝偻病．