肺性脑病时,PaCO一般应大于()
A.60mmHg
B.65mmHg
C.70mmHg
D.45mmHg
E.50mmHg
参考答案:C
—What can you see in the picture?
—I can see a farm. And there _____ a lot of animals on it. [ ]
A. is
B. are
C. be
D. am
何谓植物的生长周期?