I practiced for four hours every day and my piano teacher came three times a week to help me.

我每天练习四个小时，我的钢琴老师每周来辅导我三次。

youdao

They normally build one made of snow, for survival courses, within three to four hours.

在锻炼生存能力的课堂上，他们通常在三四个小时内就能搭建出一座雪屋。

youdao

Then I lucked into house sitting for a family friend in Paris, France for three months, which gave me the opportunity to write hip restaurant reviews and sip coffee casually for four hours a day.

后来我为我家的一个世交看房子，在法国巴黎住了三个月，在这期间我写了一些餐馆评论，而且每天都有四个小时在悠闲的品尝咖啡。

youdao

"Now we have what we would call rush hour conditions or peak travel conditions for as much as eight hours during the day - about three to four hours in the morning and similar time in the evening."

VOA: standard.2010.07.26

People wait in line for three or four hours to get her autograph.

WSJ: How to Kill a Vampire (Series)

JetBlue Airways Corp. had six diverted planes on the ground, and jetBlue officials said all its captains were acutely aware of the tarmac-delay rule, which threatens heavy fines on airlines if they keep passengers on board grounded domestic flights for more than three hours (four hours for international) without offering a chance to deplane, with certain exceptions.

WSJ: How Snow (and Libyan Soldiers) Led to Airport Logjams

Make regular stops -- every two hours for a puppy, every three to four hours for a cat or an adult dog -- so your pet can take a walk on a leash (some cats enjoy a little leash walk).

CNN: Tips for road tripping with pets