I haven't seen my grandma for a long time. I can't help her very much.
A:miss
B:missing
C:to miss
①2cm
②3.5cm
③4cm
④5cm
⑤7cm
U形管中是滴有酚酞试液的蒸馏水,向左、右两管中分别同时逐滴滴加一定量的氢氧化钠稀溶液和稀盐酸(如图所示)。下列说法正确的是( )
设定艾滋病日可以更好的宣传预防艾滋病知识,世界卫生组织将“世界艾滋病日”定在每年的( )