戊型肝炎的传播途径是（）
A.血液传播
B.飞沫传播
C.唾液传播
D.食物传播
E.蚊虫传播
参考答案：D
Working abroad for many years, he has made a big _______ and started a company of his own.
A．difference
B．fortune
C．progress
D．breakthrough
一般在妊娠多少周才能清楚显示胎头光环()
A．8周
B．8～9周
C．10周
D．11周
E．12周
