Velocitron
质谱仪
🗣️ 情景例句
I think we're going to be good friends.
我想我们可以成为好朋友。
I ask hin to tell me everything he saw.
我要求他告诉我，他所看到的每件事情。
She heard the front door open and heavy footsteps in the hall.
她听见前门被打开，走廊里响起重重的脚步声。