--- AIR IS ONE OF THE MANY PROBLEMS WE HAVE TO SOLVEA PURE B POLLUT...

39. - TRAC NGHIEM ANH 9 HKII
Tiếng Anh TRAC NGHIEM ANH 9 HKII
39.--- air is one of the many problems we have to solveA Pure B Polluted C Dust D Pleasant:40 We couldn't go on a picnic as planted --- it was raining hardA however B but C because D so