有关心脏四个腔室的说法，正确的是（）
A、互不相通
B、左右心房相通
C、左右心室相通
D、同侧的房定相通
参考答案：C
His wife ___ to catch the first train but she was too late.
A．is hoping
B．had hoped
C．has hoped
D．would hope
对有色金属加工工件在第二次划线时用（）作涂料。
A.石灰水
B.蓝油
C.红丹粉
D.紫药水
