乙型肝炎疫苗第一次接种年龄为()
A.初生时
B.1个月
C.3个月
D.8个月
E.1岁
参考答案:A
—Do you often plant trees in spring?
—Yes. Many trees _____in our school every year.
A. plant
B. are planting
C. are planted
D. were planting
以下哪一项不属于蝶窦毗邻的重要解剖结构()。
A.海绵窦
B.视交叉
C.视神经
D.三叉神经眼支
E.颈内动脉