填空题

It’s never too early to (36) your skin-or your children’s-from the sun. The sun produces (37) rays- (38) A (UVA. and (39) B (UVB.- that can cause short-and long-term skin damage. The immediate effects of harmful (40) - (41) , photosensitive (42) , and cell and (43) . damage-are bad enough. But medical experts believe that (44) Health experts also believe that UVA may weaken the immune system. (45) Using sunscreens regularly on children, for example, can reduce their risk of skin damage later in life. Sunscreens provide some protection by blocking the sun’s rays on the skin. (46) .But no sunscreen totally blocks the sun’s rays.