The police have________to look into the cause of the accident. [ ]

With the loss of labor，the old farmers ________at home had to choose less labor-intensive crops

We need to offer young students some tips of keeping them safe at school that _____them from danger.

74 It’s an untamed monkey Keep it ona or it may attack others

Do you know when Britain________war on Germany during the Second World War?—In 1993，I suppose.