21. A chair made of steel(钢) is stronger than _____ made of wood, though it costs much more.
A. that B. one C. it D. those
22. I suddenly got a feeling of soaring into the sky there was no gravity.
A. because of B. because C. so that D. for
23. the cake five parts. We will share three of them and leave the rest to Jack.
A. Separate …from B. Take …from
C. Divide … into D. Divide …from
