英语完成句子,_______________,the fish in the river disappeared.（因为

英语完成句子,
_______________,the fish in the river disappeared.（因为河水被污染了,河里的鱼都没有了）
the view of Hukou Waterfall on Yellow River is so spectacular that it attracts lots of tourists to_________________(黄河壶口瀑布的景观是如此壮观以至于它吸引了很多游客走上去仔细观察它)
Use should ________to learn more konwledage.(利用每一分钟学习更多的知识）
The two strangees often played basketball together ,so they began _________gradually.(这两位陌生人经常一起打篮球,因此他们渐渐的相互熟悉起来)