190. In tire construction, which part has the weakest strength? (A) tread (B)sidewall (C) bead.

198.Regarding the use of motorcycle rearview mirrors, which is inappropriate? (A)When traveling very close to the vehicle ahead, you should check therearview mirror to facilitate overtaking (B) Before riding, adjust the rearviewmirrors to angles and positions that make it easy to observe vehicles or roadconditions behind (C) You can adjust the rearview mirrors while waiting at ared light.