Other

Question 1

继之

Answer 1

(ji4zhi1) followed by (使釉质脱矿破坏，，继之某些细菌又使蛋白质溶解形成龋洞= makes the enamel demineralise and break, followed by certain bacteria causing protein to dissolve and create caries hole)

Question 2

如

Answer 2

(ru2) can be used as shortened form for 如果 (if)，如同 (as in the sense of a simile/as dangerous as a tiger)，比如 (such as, for example); can also be used as generic as e.g. 如你所知= as you already know

Question 3

除非

Answer 3

(chu2fei1) unless