As students, _______, we should study hard to be well prepared for the future.
A:at all
B:in all
C:after all
D:above all
下面细胞器中能合成有机物的是( )
①核糖体 ②线粒体 ③内质网 ④高尔基体 ⑤叶绿体.
Where is my jacket? Could you help _______ find it, dear?
下图是某区域不同时期示意图。下列不属于该区域20年来发生明显变化的是( )
——I feel so tired after a long walk.
——You had better have a ______.