矿井掘进通风的主要方法有利用矿井全风压通风、()和()三种。
参考答案:引射器通风、局部通风机通风
—Look! Jane has ______ tense expression on her face.
—So she does. It seems that ______ news is true.
A.a ; /
B.a ; the
C.the; /
D.the; a
夹竹桃的叶片栅栏组织发达,叶脉较稠密。