用括号内所给单词的适当形式填空
(1)—Is Grace your aunt?
—Yes, ____ (her) is.
(2)Mike and Bob ____ (be) friends.
(3)His ____ (grandparent) are in Beijing.
(4)These are her ____ (sister).
(5)—Are ____ (this) your pencils?
—No. My pencils are not black.
实验台上有一瓶标签破损的无色溶液,以下同学对该溶液的猜想合理的是()
当蛙的精原细胞进行DNA复制时,细胞中不可能发生( )
下列选项所述植物都属于藻类植物的是( )
导致中国人由学习西方“器物”转向学习“制度”的决定性因素是