看图,选出合适的句子。
A:Act like a cat.
B:Act like a duck.
C:Act like a dog.
看拼音,写汉字;
jiào shēng ____ tíng bù ____ wén míng ____ míng jiào ____
如果x<-4,则2-2+x2的值等于( )
—This history book is of great value.
—Exactly. _____ can be enjoyed from it ______ you have a deep understanding of it, however.
下列实例可以说明细胞具有全能性的是( )