下列化学用语正确的是①羟基的电子式 ②乙烯的结构简式：CH2＝CH2 ③甲烷的结构式④乙烯的结构式: C2H4⑤硫化氢的电子式
She ________ two baby cats. A．have B．has C．is
—________ they run? —Yes，they can. A．Are B．Do C．Can
—Are ________ dogs? —No，they aren't. A．it B．them C．these
________ lovely kittens! A．How B．What C．What a
Here ________ a pet shop. A．are B．is C．be
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