鼻窦包括:()
A.上颌窦
B.海绵窦
C.额窦
D.蝶窦
E.筛窦
参考答案:A, C, D, E
____ that he might lose his job, Peter always works extra hours to please his boss. [ ]
A. Worrying
B. Having worried
C. Having been worried
D. Worried
汽车行驶途中,发动机突然熄火主要是电路发生故障。