Fill in the gaps with by or with.

5 Fill in the gaps with by or with.
1 The national park was opened by the government.
2 The hill was covered with forest.
3 The panda's bowl was filled with bamboo shoots.
4 A fish's body is covered with scales.
5 Cleland Wildlife Park is surrounded by tall trees.
6 The top of the mountain was covered with snow.
7 Last weekend, the turtle nests on the beach were counted by science students.
8 The trees were cut down with a saw.