①两者都利用了高电压下电子流波长短的特点 ②两者的放大倍数远远超过光学显微镜
③两者都适合于观察细胞的内部结构 ④两者观察同一细胞样品时具有互为补充作用.
解分式方程:1x-2=3x.
I was studying for the test when the rainstorm came.(对划线部分提问)
____ were you____ when the rainstorm came?