( )——1 Everything A(seemed)B(so)difficult C (while) we D(began) the task.
( )___2 Tom A(knows)B (to solve ) the problem C (without) D (the help ) of his teacher
( )——1 Everything A(seemed)B(so)difficult C (while) we D(began) the task.
( )___2 Tom A(knows)B (to solve ) the problem C (without) D (the help ) of his teacher
1.while--when
2.knows--seems