Water is not an effective shield against the sun's more harmful rays.
水不能有效阻挡太阳中更有害的射线。
《牛津词典》
2
The most effective sunscreens protect against both UVA and UVB rays.
最有效的防晒霜既能防护紫外线A也能防护紫外线B。
3
For example, heating a home using solar panels becomes much less effective if the Windows in the house are not properly insulated or treated to keep the heat in and the UV rays out.