he is at a lossHe is at a loss what to do.和 he is at a loss as what to do 哪句正确?是不是两句都没问题?如果不加as,what to do 在这里语法上怎么解释?如果加AS,语法上又怎样解释?

he is at a lossHe is at a loss what to do.和 he is at a loss as what to do 哪句正确?是不是两句都没问题?如果不加as,what to do 在这里语法上怎么解释?如果加AS,语法上又怎样解释? He is a(n)___.He is good at drawing I don't know______or not.A.whether he is at home B if he is at home C that he is at homeD whether is he at home he is good at subject .though he plays a lot.he is a t______ student. He is nine.( ) name is Jack.Look at (He is nine.( ) name is Jack.Look at ( ).He is tall.A.He heB.His hisC.His him Who is the man is the blue?A.He is fine.B.He is old.C.He is my teacher.D.He is at home. He is a student at a medical college now. He is a serious scientist in the lab,but at home he is a loving father. Tell me where __yesterday.He was at home.A was he B is he C.he is D.he was He is good at scoring He is good at Chinese. he is a__good at sports He is good at dancingedsfsefserfwersedfsdrfwerwerwerewrwerewrwerwere he is good at fishing. he is green at his Is Mr Green ----?---No ,he is -----work.A in at B in in C at at D at in 1、He is very good at playing football.(改写同义句)He is a very . He is a business man and he is good at ____(sell)填sales