题目

用括号这所给动词的适当形式填空 1.    _________(watch)TV too much is bad for your eyes. 2. Alice often plays sports _______ (keep) fit. 3. Jim plans _______ (visit) his friends during the summer holiday. 4.We are not sure when _________(watch) the film “Life of Pie”. 5. Tom，_______(not eat) fast food . they are usually bad for our health. 答案：1.watching 2.to keep 3.to visit 4.to watch 5.don’t eat在t℃时，将 a g NH3完全溶于水，得到V mL溶液，假设该溶液的密度为ρg·cm-3，质量分数为ω，其中含NH4＋的物质的量为 b moL。下列叙述中正确的是（    ）A．溶质的质量分数为ω＝B．溶质的物质的量浓度C．溶液中c(OH-)＝D．上述溶液中再加入VmL水后，所得溶液的质量分数大于0.5ω