A:社会听证制度
B:社情民意反映制度
C:人大代表联系群众制度
D:专家咨询制度
Look at the tree. It is big and strong. It has a trunk. The trunk is big and brown. It has branches. They are brown too. Its leaves are green and beautiful. We can see some little flowers on the tree. But we can’t see the roots. They are under the ground.
有关地球形状的认识,正确的是( )
如图所示,甲、乙两个相同的玻璃瓶装水,水面高度不同,用嘴贴着瓶口吹气,发出声音的音调高的是____ ,用木棍敲打瓶口,发出声音的音调高的是____