Six minus two equals four.（英译中)

His baby is six months old.（英译中)

All man are born equal.（英译中)

He arranged his speech under four main heads.（英译中)

After walking for four hours we were beginning to flag.（英译中)

U.S. presidents normally serve a（n) ______ term.A．two－yearB．four－yearC．six－yearD．eight－yea

How often does a person dream each night？A．Two to four times.B．Four to six times.C．Every 6