A:the doorbell was rung
B:mother heard the doorbell ring
C:someone knocked at the door
D:the doorbell rang loud
下列能发生质壁分离的细胞是()
有人认为,只要挣钱多,将来做什么都行,这就是我的职业理想。你认可这种职业理想吗?
正面看到的形状是( ).
We can walk in the____ ____.