I don't know ________.
A:where is Jim
B:where does Jim come from
C:how old Jim is
①细胞核 ②叶绿体 ③线粒体 ④细胞质基质
Amy helped her grandma ______ the cat this morning.
A,B是完全相同的两块木块.如图(甲)所示,将它们叠放在水平桌面上,用作用在A上的水平力F1推它们以速度V1=1m/s匀速直线运动,测得推力F1=100N;若按图(乙)所示将它们靠着放在同样的水平桌面上,用作用在A上的水平力F2推它们以速度V2=2m/s匀速直线运动,则F2的大小为( )
She likes ____ ____, but she ____ like ____.