(2013·高考安徽卷)From space，the earth looks blue.This is ________ about seventyone percent of its surface is covered by water.
_____you _____ out the problem, Sam— Not yet, but I’m going to.
Peter, be more careful while taking the exam. .— OK, I will.
He is a poorly learned man, but he acts as though he ________. [ ]
－What are they talking ________－I am not sure. Because they are talking ______English, I don’t know English .
