正确答案: A

光的直线传播

题目：夏日炎炎,人们总喜欢躲在大树的阴影下乘凉,树荫的形成是由于 【 】

解析：A

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举一反三的答案和解析：

[单选题]27． When Johnny's parents saw the report， they were happy because ________．

they thought Johnny was not poor in English longer

解析：27．D【解析】Johnny将成绩从F改为了A，所以他父母以为他的英语提高了，故选D。

[单选题]BIt was snowing very hard for days． Jigs and Reels had nothing to eat for a day． They knew that things weren't right at home，so yesterday morning they wanted to go out． Bob put them out through a window． Because the snow was so thick outside that he couldn't open the door．

They were dogs．

解析：26．B【解析】从它们拖着野兔回来可知它们是两条狗。

[单选题]科学家利用现代生物技术成功培育出克隆羊“多莉”，多莉真正的母亲是( )

提供乳腺细胞的亲羊

[单选题]下列关于溶液的说法，不正确的是（ ）

氯化钠在20℃时溶解度是36g，则100g的氯化钠溶液中含有氯化钠36g

[单选题]

satisfied