15.Do you think No2 is __________(难) of all the problems

问题描述:

15.Do you think No2 is __________(难) of all the problems
16.We have some ________(困难)improving our English .
第一个填什么好呢?

15.the hardest (one) 或 the most difficult (one)
括号内的one可写可不写
16.difficulty
此处difficulty为不可数名词,不能用复数形式.