第四章
认真作答
21.
① ____________
② ____________
③ ____________
④ ____________
⑤ ____________
22.
① ____________
② ____________
③ ____________
④ ____________
⑤ ____________
⑥ ____________
23.
① ____________
② ____________
③ ____________
④ ____________
24.
(1) ____________
(2) ____________
(3) ____________
(4) ____________
(5) ____________
(6) ____________
(7) ____________