Nqe lus piav qhia:
1 Siv cov thev naus laus zis nruab nrab
2 high-efficiency thiab meej duab, tsis tshua muaj hluav taws xob tawg tsuas yog 1% ntawm lub teb chaws tus qauv
3 Lub teeb kov khawm, tswj nrog microcomputer, tsuas yog nias ib lub pob kom xaiv qhov cuam tshuam, cibvebuebt ceev thiab raug
4 Kev tsim kho hauv chav teeb pom kev zoo, duab hauv ib feeb, tus kws kho mob tuaj yeem kuaj tau yooj yim rau qhov siab tshaj plaws