All the invitations must sent out today.
sent 前加 be
根据句意，此处应用被动语态。
Our friend _____ like broccoli. [ ]
A. don't
B. doesn't
C. isn't
D. aren't
神经冲动在神经元与神经元之间是通过什么传递的？（）
A.突触
B.突触小体
C.突触前膜
D.突触后膜
