将一小木块分别放入盐水、纯水、酒精中漂浮时,木块受到的浮力情况是( )
A:在盐水中最大
B:在纯水中最大
C:在三种液体中一样大
D:在酒精中最大
①合成涤纶的单体是____、____
②合成涤纶的反应方程式和反应类型分别是____、____.
用所给单词填空
(1)Sometimes we ____ food at home. (2)I ____ drinking milk. (3)We often ____ CCTV news at 7:00 in the evening. (4)I ____ the Internet once a day.(5)The results for “read English books”____ fun.(6)How often do you ____ to the English corner? (7)Everyone will____ you if you need any help.(8)The sun ____ once a day. (9)Walking can ____ you in good health.(10)I____ nine hours every night.
春游湖
(宋)徐府
双飞燕子几时回?夹岸桃花蘸水开。
春雨断桥人不渡,小舟撑出柳阴来。
①处理抗原 ②呈递抗原 ③识别抗原 ④分化记忆细胞 ⑤分化效应细胞