选择填空（）3.The work（ ）at once .A .must do .B.should be done

选择填空（）3.The work（ ）at once .A .must do .B.should be done
（）3.The work（ ）at once .
A .must do .B.should be done
C.is do
（）4.The Great Wall（）by visitors all over the world every year
A.is visited B.will be visited C.is visiting
（）5.I bought two books today .One is in my hand,（）is in my bag .
A.the other B.other C.another
（）6.We can see （）stars at night if it doesn’t rain
A.thousand of B.thousands C.thousands of