下列器官适于在水中做游泳运动的是
①鳍②趾间具蹼的足③翼④趾间无蹼的足⑤鳍状的附肢⑥翼膜⑦翅⑧步行足[ ]
A.①②⑤
B.①③④
C.①⑥⑦
D.④⑦⑧
答案:A
—What's the time?
—______.[ ]
A. It's thirty to eight
B. It's at seven thirty
C. It's seven past thirty
D. It's half past seven
下列对平静状态下的呼吸叙述正确的是( )
A.吸气和呼气都是主动的
B.吸气和呼气都是被动的
C.吸气主动呼气被动
D.吸气被动呼气主动