有甲、乙、丙、丁四个轻质带电小球,用细线悬挂起来,它们之间的相互作用情况如图所示,则甲、乙带_____电荷,丙、丁带_____电荷(填“同种”或“异种”)。
同种;异种
—Are they ______ books?
—No, they aren't. They're ______ books. [ ]
A. you; they
B. your; he
C. your; her
D. your; she
Writing has ________ much of my spare time, but it has given me a great deal of pleasure. [ ]
A. taken off
B. taken down
C. taken away
D. taken up