13. There is no way to hide the freckles in my face.
我脸上的雀斑没办法掩盖。
还能这样说：
I can't find a way to hide the freckles in my face.
It is very difficult for me to hide the freckles.
谚语：
There is nothing new under the sun.
世上无新事。（来自《圣经》）
14. I'd like to know how to improve my skin.
我想知道怎样改善我的肤质。
还能这样说：
I wonder how I can improve my skin?
I'd like to know how to make my skin good.
应用解析：
improve away 通过改良为去除；
improve on 对……加以改进；做出比……更好的东西
15. Before you go to bed, you must take your make-up off.
睡觉前一定要卸妆。
还能这样说：
Remove the make-up before going to bed.
Please make sure that you take the make-up off before you go to sleep.
16. In some extent, make-up is harmful to your skin.
某种程度上，化妆对皮肤有害。
还能这样说：
To some degree, make-up does harm to your skin.
Make-up has a bad effect on your skin to some extent.
应用解析：
to a certain extent 某种程度上；
temporal extent 时间范围
17. The eyebrow can shape your frame of face.
眉毛可以修饰你的面部轮廓。
还能这样说：
The eyebrow can decorate your face.
The eyebrow has a good influence on the frame of face.
应用解析：
be in bad shape 健康状况不佳；
in no shape 决不，完全不，一点也不