【单选题】

1Laughter is a key to a good life and good health: it can diminish feelings of tension, anger, and sadness. Just as exercise conditions our bodies, frequent laughter can train our bodies to be healthier. When laughter is a regular experience, it lowers blood pressure and boosts brain chemicals that fight pain. It can also reduce stress hormones that increase vulnerability to illness, as well as increase hormones that have been shown to help produce restful sleep. Laughter is like an instant vacation in the way it changes our psychobiology.

2To make laughter a regular part of your life, try keeping a humor journal in which you record some of the amusing things that happen to you.Another technique is to create a weekly fun time to look forward to, such as watching a comedy video or having a dinner with friends that features joke telling.Another sure source of laughter is spending time with children and animals.
The author recommends all of the followingEXCEPTA．playing tricks on family and friends
B．planning a special fun time every week
C．enjoying time with pets and children
D．writing down humorous experiences