【多选题】线上课第6周《An important gift》 I was deeply moved when I received this because it was by my boyfriend. (当我收到这个礼物时我深深地被感动了,因为它是我男朋友设计的。)
【单选题】离心泵的实际安装高度超过允许安装高度时,会发生____现象。
【单选题】It is reported that______ over 1,000 factories closed down last year.
【多选题】线上课第6周《An important gift》 The has brought a lot of to my life. (笔记本电脑给我的生活带来了很多便利。)
【单选题】离心泵的实际安装高度超过允许安装高度时,离心泵会发生( )现象。