句型转换，按括号内的要求转换下列句型，每空一词。

1. Sometimes you're supposed to come early. (改为否定句)

    Sometimes you                         supposed to come early.

2. Mrs.Smith is busy. She is doing her housework now. (改为同义句)

    Mrs. Smith is                         her housework now.

3. Tom visits his grandparents once a week. (对划线部分提问)

                             does Tom visits his grandparents?

4. My pen pal is from America. (用Japan改为选择疑问句)

    Is your pen pal is from America                        ? (改为同义句)

5. The teacher said, "Don't cheat in exams, children!" (改为同义句)

    The teacher told the children                         cheat in exams.

25℃时，下列说法不正确的是（  ）

A．NaHCO₃溶液和Na₂CO₃溶液中含有的粒子种类完全相同

B．用一定浓度的NaOH溶液滴定氢氟酸，当pH＝6时，溶液中c(F^－)－c(Na⁺)＝9．9×10^-7mol/L

C．中和同浓度同体积的盐酸和醋酸，消耗的NaOH的物质的量不相同

D．用0．2 mol/L NaOH溶液滴定HCl与CH₃COOH的混合溶液(混合液中两种酸的浓度均为0．1 mol/L)，至中性时，溶液中的酸未被完全中和