平静呼吸时肺内压在下列哪个时相中低于大气压（）
A.呼气初
B.呼气末
C.吸气初
D.吸气末
E.呼气过程中
参考答案：C
Jim can drive a car, ________ he can’t ride a bike.[ ]
A. but
B. and
C. so
The early pioneers had to_____ many hardships to settle on the new land. [ ]
A. go along with
B. go back on
C. go through
D. go into
