It is pretty well understood_______ controls the flow of carbon dioxide in and out the atmosphere today.

Oil prices have risen________32 percent since last year, ________a record $84.65 a barrel on Nov.9.[ ]

Every boy and every girl as well as some teacherswho_____ to visit the museum______ asked to be at the school gate before 6 :00in the morning.

rry, can I use your computer for a while this afternoon— Sorry..

Although it’s winter now，he has to work hard in the outside．