特征侦察器
参考答案：每个神经细胞的感受野都有其侦察特定特征的功能。
—How does Jack usually go to school?
—He ______ ride a bike, but now he ______ there to lose weight. [ ]
A. used to, is used to walk
B. was used to, is used to walking
C. was used to, is used to walk
D. used to, is used to walking
国际天文学联合会在1922年将星空划为（）个星座。
A、88
B、29
C、46
