教师借班上课，总会碰到因不了解学生、不熟悉环境，而导致教学预设不当、师生无法有效沟通产生的教学阻隔现象。

While conducting a demonstrative lesson in an unfamiliar class, a teachers four effective ways are enthusiasm, humor, instruction, and a pre-class ta.

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鲑鱼生存所需的河流由于人类的开发而很快被阻隔和污染，过去多产的鲑鱼群回游现象如今已不多见。

Salmon need rivers which are quickly blocked and fouled by human development, and the teeming runs of old are now rare.

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能调整肤色不均、暗黄现象，勾勒面部轮廓，形成层次分明的靓丽脸庞，同时阻隔外界刺激因素，抑制黑色素形成。

Improves uneven skin tone, reduces yellowish skin and carves out a sharp and beautiful face contour while prevents melanin formation and blocks environmental irritation.

youdao

能调整肤色不均、暗黄现象，勾勒面部轮廓，形成层次分明的靓丽脸庞，同时阻隔外界刺激因素，抑制黑色素形成。

Improves uneven skin tone, reduces yellowish skin and carves out a sharp and beautiful face contour while prevents melanin formation and blocks environmental irritation.

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