现在进行时（be + v-ing） — 英语填空题
题目
用括号中所给动词的适当形式填空：It is a sunny afternoon in the forest. Look! A panda ___ (eat) bamboo under the tree. Two birds ___ (sing) in the tall tree. A rabbit ___ (run) on the grass. The ducks ___ (swim) in the river.