1) All he thinks about is sex.

2) What sex is your dog?

3) A taboo against sex before marriage.

4) He took a vow to abstain from alcohol/smoking/sex.

5) Abstain from sex or use condoms.

6) Sex is considered taboo as a topic for discussion.

7) The tabloid papers labelled him "an evil sex monster".

8) Testosterone is the male sex hormone.

9) What sex is your cat?

10) Please indicate your sex and date of birth below.

11) What sex is this fish?

12) He shows a precocious interest in the opposite sex.

13) She is exempt from sex discrimination laws.

14) How can you tell what sex a fish is?

15) Is there too much sex and violence on TV?

16) Is there a taboo against sex before marriage in your society?

17) We know some sex offenders dupe the psychologists who assess them.

18) Discrimination on the grounds of sex or race is unlawful.

19) Police are looking for a sex pest who is frightening late-night travellers.

20) She still has the energy and sex appeal of a woman less than half her age.

21) Mention sex therapy and most people will titter in embarrassment.

22) The population is categorized according to age, sex,(http://sentencedict.com/sex.html) and social group.

23) She had that indefinable something that went beyond mere sex appeal.

24) He cared for her as a whole person rather than just a sex object.

25) The students we spoke to were surprisingly uninhibited in talking about sex.

26) You are playing Russian roulette every time you have unprotected sex.

27) At that age they can start becoming shy with the opposite sex.

28) In a position of authority, a weakness for the opposite sex leaves you open to blackmail.

29) How well off you are in old age is largely determined by race, sex, and marital status.

30) The law requires equal treatment for all, regardless of race, religion, or sex.