【单选题】
20. ______ you can’t answer this question, we have to ask someone else for help.
①
Although
②
While
③
Whether
④
Since
【单选题】
20．神经系统的大体解剖结构叙述错误的是
①
A-中枢神经是指脑和脊髓；外周神经是指脑神经和脊神经、内脏神经
②
B．脑干是指延脑、脑桥、中脑、伺脑
③
C．第3、7、9、10对脑神经中含副交感神经
④
D．脑和脊髓外表面由硬膜、蛛网膜、软膜包裹
⑤
E．脊髓断面外周为H形灰质
【单选题】
20. Only when he had handed in his exam paper ____ he had made several mistakes.
①
he has realized
②
does he realize
③
has he realized
④
did he realize
【单选题】
20. The joke told by Tom made us_____, so our maths teacher couldn’t make himself _____.
①
to laugh; hearing
②
laughing, heard
③
laughing; hear
④
laughed; heard