She was ill, she still went to work and tried her best to do the work.
A:though
B:because
C:if
D:but
人的体细胞内含有____染色体,生殖细胞内含有____染色体.
如图所示,一块橡皮用细线悬挂于O点,用铅笔靠着线的左侧水平向右匀速移动,运动中始终保持悬线竖直,则橡皮运动的速度( )
填一填。
弯弯的月儿像____,闪烁的____像钻石。