2019年mpacc考试英语真题——连词42

{01}It is well-known that atmosphere gets thinner and thinner ________ the height increases．
A.while
B.when
C.as
D.with
解析：句意：众所周知，随着高度的增加，大气越来越稀薄。as意为“随着……的变化”。
本题选C。
{02}You must work out the problem all by yourself, ________ it is very difficult．
A.as if
B.even
C.but
D.even though
解析：even though/even if表示“即使”，引导让步状语从句。as if/as though意为“好像”，引导方式状语从句。
本题选D。