一筐苹果，2个2个地拿，3个3个地拿，4个4个地拿，5个5个地拿都正好拿完没有余数，这筐苹果最少应有（　　）个．

下面是李商隐的诗《银河吹笙》，中间两联残缺，请根据律诗的特点，选出恰当的一项（  ）
怅望银河吹玉笙，楼寒院冷接平明。
重衾幽梦他年断，______    ______。
月榭故香因雨发，_____    _______。
不须浪作缑山意，湘瑟秦箫自有情。

Valentine's Day(情人节) is on February 14th every year. On this day, people send valentines(情人卡)to their loved ones, Valentine's Day is a special time to tell how much you care about a person.
Many people send candy in hearted shaped("心"状的)boxes to people they love. Flowers are also presents that people send on Valentine's Day. Valentine cards with words are often used by many people.
Can you guess who gets the greatest number of Valentine cards in the United States each year? Is it mother or father, sister or brother? Is it uncle or aunt? Is it the special friend? No, it isn't!
Mothers get a lot of cards, but school teachers get the most each year. Do you know who sends the most? Children do. Children send five times as many on February 14th as adults do.

下列各式中，a和b成反比例的是（   ）