For most children, the most useful way of spending their time is playing a game. It doesn't matter 1 the game is. Things become better when they need a (n) 2 to play with. On the one hand, it is quite 3for the development of a child's personality (个性) to win and to 4 the best ways to get that. On the other hand, if a child only cares about 5 , then for him, playing a game is funny only when he wins. Or if he finds a better partner, he will get 6and he doesn't want to go on playing.

 It's parents’7to make their children know that: you can’t always win and there are many unpleasant moments8 when you have to learn how to lose. The idea is to compete, to prove you are good, not only to win.

In a word, playing a game is not funny only when you win. It is funny9 you enjoy it and try your best to win. If you are just a little bit unlucky, don't10 a lot. You will surely prove your abilities some other day.

下列现象中是描述生物因素对生物影响的是（　　）