“变宽”用英语怎么说？

河流转向东流时河道大幅度变宽。The river widens considerably as it begins to turn east.小路在和公路相交的地方变宽了。The track widened as it met the road.过了一会儿,路变宽了,他们也走得更快了.After a while the road opened up and they traveled more quickly....