A:X是SO 2,Y是NaOH溶液
B:X是CO 2,Y是石灰水
C:X是HCl,Y是Na2CO3溶液
D:X是NO,Y是石灰水
常用抗生素“先锋Ⅵ”为粉末状固体,每瓶含“先锋Ⅵ”0.5g,注射时应配成质量分数不高于20%的溶液,则使用时每瓶至少需加入蒸馏水( )
①SiO2﹣→Na2SiO3;②CuSO4﹣→CuCl2;③SiO2﹣→H2SiO3 ;④CuO﹣→Cu(OH)2;⑤Na2O2﹣→NaOH.
find, eraser, book, some, a, is, my, too, where, under
This is my desk. Two____ are on it. One is my English book, and the other (另一本) is my math book. You can also see (也能看见)____CDs on the desk. The CDs are ____. My pencil box is on the desk,____. A pen,____ eraser and a ruler ____ in it. The pen is black, the____ is yellow, and the ruler is white. ____ is my pencil? Aha, it's under the desk. Is my computer game ____the desk,too? No, it isn't. Where is it? I can't____it in my room.