题型:完形填空 完形填空 The Spring Festival(春节) is the Chinese New Year's Day. It usually comes 1 February. Everyonein China 2 the Spring Festival very much. When the Spring Festival 3 , Li Hong usually 4 his parents clean their house and 5 some shopping and other housework. On that 6 everyone in Chinaeats dumplings, New Year's cakes, and other good 7 . Li Hong likes New Year's cakes. But Wang Hai dumplings are 8 than New Year's cakes. The Chinese people 9 the New Year's cakes anddumplings in their houses . How 10 they are!( )1. A. after ( )2. A. has ( )3. A. goes ( )4. A. helps ( )5. A. buys ( )6. A. morning ( )7. A. food ( )8. A. smaller( )9. A. find out( )10. A. happy B. on B. like B. comes B. makes B. does B. evening B. drinks B. better B. buy B. delicious C. in C. remember C. reaches C. gets C. goes C. day C. Vegetable C.bigger C. eat C.lovely D. by D. likes D. hears D. takes D. carries D. afternoon D. fruit D. sweeter D. sell D. great 查看答案
题型:单项选择题 A1/A2型题 生物碱显碱性的原因是因为氮原子上有孤对电子能够接受质子,凡是能够增加氮原子电子云密度,碱性增强;减弱氮原子电子云密度,碱性减弱。下列因素除哪项外影响生物碱的碱性()A.诱导效应B.立体效应C.共轭效应D.氮原子的杂化方式E.酚羟基的数量多少 查看答案