— I can't find my _____________.
— You're wearing them.[ ]
A. books
B. boots
C. dress
答案:B
溃疡型食管癌的典型表现是()
A.牵引性憩室
B.食管节段性环行狭窄
C.食管内充盈缺损
D.龛影
E.食管全程扩张,末端呈鼠尾状
飞机平飞时保持等速飞行的平衡条件是()
A.升力等于重力,推力等于重力
B.升力等于重力,推力等于阻力
C.升力等于阻力,推力等于重力