对于脊髓肿瘤，正确的是()

A．髓内肿瘤痛温觉障碍自下向上发展

B．髓内肿瘤痛温觉障碍自上向下发展

C．髓外肿瘤深感觉障碍自上向下发展

D．髓外肿瘤痛温觉障碍自上向下发展

E．髓内肿瘤深感觉障碍自下向上发展

It’s easy to _________ this camera , while putting the pieces together is quite difficult, so you must keep the directions well.

A． take over

B． take apart

C． take down

D． take up