书面表达。

     根据信息完成小作文。

    一天，Maria的好朋友Sarah邀请她去家里做客，不巧的是Maria要为爷爷过90大

寿，所以她提前离开了。Maria写了一封感谢信，并说明她提前离开的原因，请你补

全感谢信，每空一词。

Dear Sarah,

     1 _______ for inviting me to your house on Friday. I really enjoyed meeting your family.  And

your baby sister is really 2. _______ I had a 3_______ time. I'm 4. _______I had to leave early,

but I had a family dinner . My grandfather was having his 5._______ birthday party!

晶闸管整流电路中，通常采用主电路与触发电路并配合（）的方法来实现同步。

A、使用同一电网电源

B、同步变压器采取不同的接线组别

C、阻容移相

D、中心抽头

E、同步电压直接取自整流变压器