A:as far as, had
B:as well as, have
C:as long as, to have
D:so long as ,having
下列现象中,属于人口增长过慢造成的是( )
抗生素能够杀死或抑制某些病菌,但如果长期使用或滥用抗生素,就会使病菌的抗药性增强而失去治疗效果. .(判断对错)
数列{an}满足an+1=an﹣3(n≥1)且a1=7,则a3的值是( )