2019年mpa考试英语真题——形容词775

{01}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
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。
本题选B。

{02}________ with a gas which is lighter than air, a balloon can float in the air.
A.When filling
B.When filled
C.Filling
D.Having filled
解析：
本题选B。