Birds are seldom heard _______at night.A.sing B.singingC.to sing D.to be singing

Birds are seldom heard _______at night.A.sing B.singingC.to sing D.to be singing Birds are seldom heard _____at night.A.sing B.singing C.to sing D.to be singing hea penguins are birds,but they are not l____ most birds. They are birds 写出问句 are the birds in the Where are the birds中文 you are birds and beasts hea的hea是什么意思 hea的hea是什么意思 hea是什么意思 hea是什么意思? hea是什么意思? Birds There are some birds s___in the tree. there are many birds in the sky There are some birds singing( )the trees there are three birds in the