正确答案:

题目：原子，分子，离子都是构成物质的微粒 。 （ ）

解析：√

查看原题

举一反三的答案和解析：

[单选题]______more,andyou’llimproveyourspokenEnglish.

Speak

[单选题]．碳元素与氧元素的本质区别是

质子数不同

[单选题]AMan invented a lot of sports equipment． The first true piece was the ball．

many different games with balls

解析：21.A【解析】由第四段第一句“Before long they in- vented a lot of ball games...”可知。

[单选题]我国南方地区主要的糖料作物和油料作物分别是：

甘蔗、油菜

[单选题]小明在小丽的东南方向，小丽在小明的 方向。 （ ）

西北

[单选题]He used to be _____, but now he likes to meet and talk to new people.

shy

[单选题]10．—_________are you staying?—For a week．

How long