Teachers are not happy when they find in class their students sending ________ to their friends by m

Teachers are not happy when they find in class their students sending ________ to their friends by mobile phone.

A.letters

B.messages

C.notes

D.informations

答案及解析： B

解析：

send messages“发短信”，letter“信件”，note“便条”与句意不符，information不可数名词无复数形式。