I can hear many birds________ in the trees.A.to sing B.singe

I can hear many birds________ in the trees.A.to sing B.singe Listen!I can hear many people___ in the next door.A.to sing Listen!Can you hear birds（ ）in the tree?A.sing B.to sing C.s In spring,we can hear birds -----(sing) in the trees I often hear her( )in the next room.a/sing b/is singing c/to We often hear a lot of birds ___(sing) in the trees in the m --- How many birds can you see in the trees? --- I can see b Listen!I hear the girl ( ) in the next room.A.singing B.sing Can you hear a girl( )in the next room?Who can it be?A.sing I hear Miss Silver ___well.(A sings B sang C to sing D sing) In the country,I can hear the birds____.填sing or singing? Trees can help _____ the air in the city.A to clean B clean