⑴What is this? ____           A. Thursday.

⑵What are these?____        B. Yes, it is.

⑶What is she wearing?____   C. They're shorts.

⑷Is this a new cap?____      D. She is wearing a blue skirt.

⑸What day is today?____     E. It's a new T-­shirt.

①利用VSEPR模型推断分子或离子的立体构型。

CS₂____;

AlBr₃(共价分子)____。

②有两种活性反应中间体微粒,它们的微粒中均含有1个碳原子和3个氢原子。请依据下面给出的这两种微粒的球棍模型,写出相应的化学式:

____;

____。

③按要求写出第二周期非金属元素构成的中性分子的化学式。

平面形分子____,三角锥形分子____,四面体形分子____。