When you ______ a difficult task, try to continue with it and finish it.
A:give
B:are giving
C:gave
D:are given
在一个不透明的口袋中,装有若干个红球和4个黄球,它们除颜色外没有任何区别,摇匀后从中随机摸出一个球,记下颜色后再放回口袋中,通过大量重复摸球实验发现,摸到黄球的概率是0.2,则估计盒子中大约有红球( )