Ted's mother was cooking while he his homework.
A:is doing
B:does
C:was doing
D:did
如图,若要让反射光线中目标,在激光笔不动的情况下,可将平面镜( )
关于制备牛肉膏蛋白胨固体培养基,叙述错误的是( )
读古诗《咏柳》,了解作者
贺知章,字____,号____,汉族,诗文以____见长。